Method of permafrost rock bedding delimitation
SUBSTANCE: invention refers to gas and oil industry and can be used, in particular, to select technology of well building and construction, as well as to monitor technical condition thereof inside permafrost rocks (PFR) and in permafrost zone. According to proposed method, a well is drilled, temperature is measured in depth of a well and then geothermic gradient is defined. On the basis of the results of these measurements, lower boundary depth of PFR ground bed is defined. For this purpose, before temperature in well depth is measured, a casing string (CS) is let down in a well along its sidewall and cemented. After cementing of CS is completed, measurements of temperature inside a well are carried out in the process of cement setting during thermal recovery. The results of temperature measurements are used to plot temperature curve of a well depending on the depth of a well. According to the depressed temperature level of the temperature curve, upper zone of PFR mass bedding inside it and lower zone under it are indicated. Lower zone is the zone of thawed, cooled and/or waterflooded rocks with higher temperature level when the average temperature gradient does not exceed 0.02-0.05°C/m. Between them, an intermediate transition "step" zone is indicated. This is a zone with rapid increase in temperature and high value of temperature gradient (G = 0.06-0.45°C/m and higher). According to the temperature curve and indicated connection point of the "step", which is an intermediate, high-gradient temperature zone with lower thawed, cooled and/or waterflooded zone, the depth of PFR mass bedding is defined. Inside PFR mass, separate local zones of thawed rocks with higher temperature level, frozen zones with depressed temperature level and intermediate high-gradient temperature zones lying between them are indicated simultaneously. According to junction points of intermediate zones and thawed zones, the boundaries between thawed and frozen zones located inside PFR mass are defined. In this case, temperature measurements inside a well are made using a highly sensitive thermometer with intervals of temperature measurement in depth of not more than 0.1-0.2 m.
EFFECT: more accurate definition of bottom depth of permafrost rock mass.
2 cl, 2 dwg
The invention relates to gas and oil industries and can be used, in particular, for the choice of construction technology and designs as well as in the control of their technical condition in permafrost (MMP), in permafrost.
In the process of construction and operation of wells in the areas of MLM you need to improve the quality of construction and reliability of operation, which involves taking into account the depth of the sole MMP influencing the choice of the construction of wells (depths to run casing - direction, the conductor, the insulation structure), to conduct monitoring of their technical condition in permafrost.
There are different methods and ways of defining the boundary of occurrence of a sole MMP using standard data logging (gradient-probe potential-probe), thermometry, acoustic method for detecting boundaries of the occurrence of permafrost (see, for example, Ermilov O.M., Degtyarev BV, Kurchikov, A.R., Construction and operation of gas wells in the Far North: thermal and geochemical aspects. Novosibirsk, 2003, SB RAS, 223 S. and Bulls IU, Dmitriev E Drilling of water wells in the Northern areas. Leningrad, Nedra, 1981, 128 S.).
However, these methods do not provide sufficient accuracy in determining the boundaries of the occurrence of frozen and thawed rocks and is Oswy MMP, because of the conditions of measurement, with insufficient accuracy of the equipment used, for example, thermometric equipment and underdevelopment of the methods used for selection in the context of thawed and frozen soils and the soles of MMP, including geophysical methods without special data thermometry and standard logging.
Closest to the invention to the technical essence and the achieved result is a way of defining the boundaries of the occurrence of permafrost, which consists in the fact that the drill hole, measured geothermal gradient and the results of measurements determine the depth of the lower boundary of occurrence of MMP (see patent RU No. 2125149, CL EV 36/00, 20.01.1999).
This method of defining the boundary of occurrence of MMP assumes that the dimension of the geothermal gradient in the context of the permafrost zone and nistlerooy rocks and logging is carried out in well with the range of 25-50 m and cause the received temperature data in the form of lines on the graph in accordance with geothermal gradients in frozen and non-frozen areas, and on the points of their intersection is judged on the depth of the lower boundary of occurrence of MMP. However, a significant drawback of this method of determining the boundaries of MLM is the fact that the measurements do not take into account the number of terms in the research, namely the Pris shall result in the context of bigradient (relic) frozen zone, the interval of occurrence of relict MMP and specific conditions for the measurement of temperatures in the borehole, namely after a long vistani or after cementing columns and after some time.
In all the frozen area in the context it seems bigradient temperature zone (zero gradient), and non-frozen area with higher value averaged gradient, without considering the intermediate zone, is actually present between the two marked areas when westone, for example, after the cementing of columns, which makes a significant error in the interpretation of the measurement results in the specified way and inaccuracy in determining the depth of the sole MMP.
This method does not allow to allocate a melt zone that can occur in the thickness of the MMP. The increased interval depth, through which the measured temperature, and the omission of precision in the use of thermometric instruments contribute additional uncertainty in the interpretation of the results thermometry.
Task to be solved by the present invention is directed, is to improve the accuracy in determining the depth of frozen and thawed rocks and soles of MMP, including the selection of the boundaries of the occurrence of frozen and thawed rocks and soles MMP.
The technical result achieved from the use of the education of the invention, is the elimination or at least reduction of error in the determination of the depth of the frozen and thawed rocks in the section.
The problem is solved and the technical result is achieved due to the fact that the method of determining the boundaries of the occurrence of permafrost is that the drill hole, measure the temperature at the depth of the well and determine the geothermal gradient, and the results of measurements determine the depth of the lower boundary of occurrence of the soles of permafrost), before measurement of the temperature at the depth of the borehole along its side wall lowered into the well casing and cement, after the cementing of the casing of the borehole temperature measurements in the borehole is carried out in the process of curing of concrete during recovery temperature, and the results of measurements of temperatures used for construction of the temperature curve in the borehole, depending on the depth of the well, wherein the temperature curve low level temperatures it distinguish upper zone of deposition of the strata MMP and under it emit lower zone melted, cooled and/or water formations with higher temperatures, with an average temperature gradient not exceeding 0,02-0,05°s/m and between them produce an intermediate, transition zone - "step" with a dramatic increase in the pace of the atmospheric temperature and the high value of the temperature gradient (G=0.06 to 0.45 in° S/m or more), the temperature curve on the identified connection point "steps" - intermediate high-temperature zones with lower melt, chilled and/or flooded area, determine the depth of the sole thickness MMP, and simultaneously within strata MMP allocate separate (local) zone melt rocks with higher temperatures, frozen areas with low temperatures and intermediate - high temperature zones between them, and the points of intersection of the intermediate zones of melt zones define the boundaries between thawed and frozen zones located inside the thicknesses of the MMP, and the measurements temperatures in the borehole manufactured using a highly sensitive thermometer (HFT) with interval measuring temperatures at a depth of no more than 0.1 to 0.2 m
Measurements of the temperature detection depth soles MMP in the process of hardening of the cement behind the casing is preferably carried out not earlier than 15-30 hours after completion of the cementing of the casing, and when the injection of the cement behind the casing of the last completely cover thickness MMP.
Analysis of the works measured in accordance with the above procedure shows that the singularities of a recovery thermal field after the termination of heat in the effects of measured temperatures after cementing, specifically, after completing the injection of the cement behind the casing, overlapping MMP during the curing of the cement, when the recovery temperature. However, when analyzing the measurements distinguish in addition to frozen and non-frozen - thawed zones intermediate high-temperature zone, which in the interpretation of temperature measurements after completion of the cementing columns improves the accuracy in determining the depth of a sole thickness of MMP. It was found that in the intermediate zone on the "step" there has been a sharp increase in temperature and temperature gradient up to G=0,06-0,45°s/m and more, as well as the heat flux as a result of thawing of MMP on the sole MMP due to the temperature increase caused by the receipt of heat of hydration of cement in his grasp. On the identified connection point "steps" - intermediate (transitional) high gradient (G=0.06 to 0.45 in°s/m and more) temperature zones with lower melt zone at elevated temperatures compared to the frozen area with a lower gradient (no more than G=0,02-0,05°s/m) temperature compared to the intermediate zone, determine the depth of the sole thickness MMP. If thicker MMP melt rocks in her plots in depth with elevated temperatures in the melt, with low temperatures in the frozen rocks and about eroticne zone between them with high temperature gradients and the points of intersection of the intermediate zones of melt zones define the boundaries between thawed and frozen zones, located inside the thicknesses of the MMP.
In the course of the study it was found that the measurements of temperatures in the borehole must be using a highly sensitive thermometry (HFT), i.e. with an accuracy of measurement of temperature in degrees to the second, the third digit after the decimal point and interval measuring temperatures at a depth of no more than 0.1 to 0.2 m
Figure 1 shows the results of measurements of temperature HFT-BCC (assessment of the quality of the cement columns) at well # 1 gas field.
Figure 2 shows the temperature gradient according to the results of measurements of temperatures at well # 1 gas field.
The method is implemented as follows.
In a pre-drilled hole with an interval of 0.1-0.2 m were measured temperatures and determination of the geothermal gradient. The values obtained were processed and deposited on the graph (see figure 1 and 2).
Measurements of temperatures in the borehole No. 1 gas field in the area of MSE are presented in figure 1, was conducted 24 hours after the cementing of the production casing with a diameter of 168 mm Upper zone (position 1) with the MMP is allocated to low temperatures and high amplitudes of their changes in the permafrost zone, as well as sudden changes in temperature gradients (see figure 2) with high absolute values of the gradients to a depth of 450 m depth the ins 430 m and to a depth of 450 m there has been a sharp increase in temperature (position 2 in figure 1) and a high temperature gradient (see 2). This zone (position 2 in figure 1 and 2) is marked as intermediate, and the upper point (position 4) at a depth of 450 m determines the depth of the NPMoccurrence soles MMP, below which lie thawed, chilled, low-temperature rocks (lower area - position 3). At well # 1 (see figure 2) is observed in the depth interval 430-450 m in the intermediate zone of sharp growth and large values of the gradient "G" temperature (0,06-0,45°s/m), and deeper below the soles of MMP, there is a decrease in gradient "G" up to 0.02-0.05°s/m and its stabilization in the range of these values with the approach to stationary values of the deep temperature gradient during the stabilization of thermal field. At the top of the frozen zone in the case of relic MMP adjacent to the intermediate zone, the temperature gradients is zero or close to zero. When conducting measurements were used highly sensitive thermometry (HFT) with an interval of temperature measuring 0.1 m, which allows you to more precisely select the depth of the soles of MMP. Within strata MSE of the proposed method are also highlighted melt rocks and boundaries of intervals of depths (see figure 1, 2 position 6), the occurrence of melt rocks in the allocation of the respective intermediate zones (see figure 1, item 7) and points (item 8) their junction with the melt zones (item 6).
In the course of the research it was found that depending on the type of use is imago grouting material and features of its hydration, and depending on temperature and pressure conditions in the annular space in the borehole during the measurement temperature may be at least 15-30 hours. Depth measurements of temperatures in the described method can be carried out inside the well, in case the casing and into the annular space during the descent for the outer columns (direction, conductor) thermometric tube (TT) to depths of 50-100 m and more. If this TT can descend and be installed, as for the outer column - direction or a conductor, and in the annular space, for example, between the direction and the conductor. Using TT with a large internal diameter (20-41 mm)and a thin tube with a diameter of less than 20 mm Thermometric tube filled with non-freezing liquid, which enables the measurement of temperatures and when restoring negative temperatures in permafrost.
Depth measurements of temperature HFT-the BCC in wells can be carried out once or several times within the case of the column, for example, 15, 24, 36 hours after the injection of the cement, and in TT at any reasonable time to inspection change of temperature (thermal) conditions at the well, allowing multiple temperature measurements used for different backfill material and thermobaric conditions in the wells to determine the optimal timing of thermometry method to detect edges, the depth of frozen and thawed rocks and soles MMP in permafrost.
The results of studies carried out in the oil fields, also showed the possibility of defining the boundaries of the occurrence of MMP in oil wells. Sole MMP is also highlighted by thermograms HFT-BCC casing, including the conductor. Studies on oil mestorozhdenii in the area MMP allowed us to identify a "step - intermediate zone" on thermograms for the conductor 15 wells and to determine the points of intersection of these areas, identified thawed zones according to the method, the depth of the soles of the MMP. The data according to the method, the images were compared with the data selection soles MMP data processing standard logging (IC), the method of "MOCK" (see, for example, the WFD 39-1.9-015-2000. Guide thermometric methods of quality control of construction, mounting boreholes in permafrost and low-temperature rocks. Moscow, 2001, OAO Gazprom, Gazprom VNIIGAZ LLC, IDC Gazprom", 63 C.), which showed that the depth of the sole MMP defined on different bushes, via the described method (thermograms HFT-BCC) ranged from 260 to 330 m, and according to the UK - from 272 to 318 m
Thus, certain depth soles MLM wells simpler described thermometric method and Dunn is m IC differ on 4-12 meters as shown in the examples.
The depth of the sole thickness MMP - lower bound, which is celebrated on the ice content of the rocks 3 kg/m3and more on well # 1 identified according to the UK - 454 m and according to thermometric method HFT-the BCC - 450 m (see figure 1, 2) and the difference in determining the depth was 4 feet In the same time, the sole of the permafrost zone according to the UK can only be determined in the absence of the water content section below identified sole thickness MMP.
In General, the efficiency of the described method is that the study of permafrost conditions is carried out directly on exploration and production wells on the basis of geophysical methods of investigation, thermometry without special drilling permafrost boreholes, without selection and research core, which allows to obtain significant savings in time and money, as well as to explore these conditions in all wells in the field with the construction of schematic map of permafrost conditions (depths soles MMP, watering etc.), varying in area fields.
The proposed method can be used in the oil and gas industries and allows you to define the lower boundary of occurrence of the soles of the permafrost on the basis of the obtained temperature data.
1. The method of determining the boundaries of the occurrence of permafrost is orod, namely, that drill hole, measure the temperature at the depth of the well and determine the geothermal gradient, and the results of measurements determine the depth of the lower boundary of occurrence of the soles of permafrost), characterized in that before the measurement of temperatures at the depth of the borehole along its side wall lowered into the well casing and cement, after the cementing of the casing of the borehole temperature measurements in the borehole is carried out in the process of curing of concrete during recovery temperature and the measured temperature is used to build the temperature curve in the borehole, depending on the depth of the well, wherein the temperature curve low the level of temperature it distinguish upper zone of deposition of the strata MMP and under it emit lower zone melted, cooled and/or water formations with higher temperatures, with an average temperature gradient not exceeding 0,02-0,05°s/m and between them produce an intermediate, transition zone - "step" with a dramatic increase in temperature and a high value of temperature gradient (G=0.06 to 0.45 in°s/m and more), the temperature curve on the identified connection point "steps" - intermediate high-temperature areas with lower melt, chilled and/or flooded area determine the GLA is inu occurrence sole thickness MMP, and at the same time within strata MMP produce some of the local zone of melt rocks with higher temperatures, frozen areas with low temperatures and intermediate - high temperature zones between them, and the points of intersection of the intermediate zones of melt zones define the boundaries between thawed and frozen zones located inside the thicknesses of the MMP, with measurements of temperatures in the borehole produced using a highly sensitive temperature interval measuring temperatures at a depth of no more than 0.1 to 0.2 m
2. The method according to claim 1, characterized in that the measurement of temperatures by determining the depth of the sole MMP in the process of hardening of the cement behind the casing to be held not earlier than 15-30 hours after completion of the cementing of the casing, and when the injection of the cement behind the casing of the last completely cover thickness MMP.
FIELD: oil and gas industry.
SUBSTANCE: invention relates to the oil and gas industry, particularly to the methods of designing the development of the gas-condensate fields (GCF) with the high content of the condensed fluid in the native gas (NG). For this purpose, in developing GCF, the exchanged gas sample of the initial composition is created in the chamber pVT, at the formation conditions. The staged modeling of the GCF developing process is performed in mode of exhaustion by differential condensation (DC) due to gas bleeding from the chamber pVT. The volume and mass of the separating gas, bumping and degasified condensate are determined. Sampling with the following calculating the NG density for each developing stage and forecast of changes in the NG density is performed by use of the analytic relationship. For each DC stage and after creating the thermobaric conditions, the mass of loaded NG, mass of NG bled from the chamber pVT, and the mass of NG escaped as the wet gas condensate, are determined. The mass of the NG left in the chamber pVT is calculated at each stage by using the balance method. At that, the NG density at the initial formation conditions is determined by the specified relations. The volume and mass of the NG conditioned to the standards, and loaded into the chamber pVT, density of the NG conditioned to the standards for the current formation pressure, volume of the NG in the chamber pVT at the current developing stage and conditioned to standards, NG density for the current formation pressures at formation conditions, the volume of the chamber pVT taken by the residue NG in gas phase at the current formation pressure, the volume of the chamber pVT taken by the NG at the initial formation pressure and the volume of the retrograde wet gas condensate precipitated in the chamber pVT at the current formation pressure are determined by specified relationships, and the change in NG density in GCF developing is forecasted at standard and formation conditions.
EFFECT: simplification of method for designing gas-condensate formation development, research time reduction and increased precision.
1 dwg, 6 tbl, 1 ex
SUBSTANCE: invention refers to the mining industry, namely to the drilling equipment, and is designed for research of optimal drilling mode parameters based on the temperature rise criteria in the contact zone of the drilling tool and the rock. The device includes the core holder with a rock sample as the core installed at the spindle of the core drill, the thermal frictional tool, the optic cable laid along the gallery hole of the tool frame with its end at the friction tool end plane, connected in series with the receiver-amplifier and the registering device, the core tube with a nozzle for water input, the anti-spatter protection cover, and the water collector with water drain. There is a gallery hole connecting the internal and the external cavities of the tool in the thermal friction tool frame. This allows to cool the optic cable with water coming to the core tube, which reduces the additional IR-radiation being a hindrance to the main signal.
EFFECT: setting the optimal drilling mode parameters by the contact zone temperature of the tool and the rock, as measured on the testing bench.
2 cl, 2 dwg
SUBSTANCE: invention refers to the mining industry, namely to the drilling equipment, and is designed for research of optimal drilling mode parameters based upon the temperature rise criteria in the contact zone of the drilling tool and the rock. For this purpose, the temperature of the contact zone of the drilling tool and the rock is measured by the pyrometry method by rotating the rock sample while the tool remains steady. IR-radiation is directed to the receiver by the means of a fiber optic cable laid through the tool's cannelure and connected to the IR-radiation receiver. Then, it is transformed into analog signal, got amplified and fed to the recording device. Besides, cold water is fed to the cannelure through the tool inner cavity, in order to reduce the hindrances from additional IR-radiation of heated fiber optic cable walls by cooling the cable down. The working end of the optic cable is insulated from the water-bearing cavity with sealer.
EFFECT: setting the optimal drilling mode parameters by the contact zone temperature of the tool and the rock, as measured on the testing bench.
FIELD: oil and gas production, particularly to perform measurements during well drilling (initial well completion) to obtain information concerning temperature and pressure of drilling mud flow injected in well directly from well bottom to area of drilling mud flowing through jet bit nozzles and turbine blades, as well as in hole annuity of the well after rock cutting by bit and turbine blades and crushed rock washing-out from well bottom.
SUBSTANCE: device comprises sub with container connected to outer surface thereof installed between drilling pipe or tubing assembly and drilling tool assembly. The container has orifices in upper and lower parts thereof. Self-contained measuring instrument is installed inside container. Two mutually independent temperature and pressure sensors are arranged in upper and lower parts of measuring instrument so that temperature and pressure are located in immediate proximity to container orifices. Distance between container orifices does not exceed two meters. Heat-insulation sleeve is installed in central container part in fluid-tight manner. Self-container measuring instrument may be supported by springing support and does not touch container body.
EFFECT: increased reliability of results obtained during thermobaric drilling mud or flushing liquid condition measuring in pipe string and annular spaces simultaneously, possibility to take measurements during any technological operation, well construction and development.
4 cl, 2 dwg
FIELD: oil production, particularly thermal field investigation inside producing wells.
SUBSTANCE: method involves lowering downhole cable provided with temperature meter in well, wherein downhole cable is arranged outside production string. Fluid temperature is measured by means of downhole measuring-and-stabilizing unit including at least one temperature sensor and parameter stabilizing device. The temperature sensor is installed so that sensing member thereof touches production string wall or production string clutch wall or is located in immediate proximity thereto. Crystal resonators are used as the temperature sensors. Land-based measuring assembly includes frequency electronic measuring module. The land-based measuring assembly and conductive signal transmitting communication line thereof with measuring-and-stabilizing unit may simultaneously read signals from all temperature sensors if number of temperature sensors exceeds 1.
EFFECT: increased measuring accuracy in working well in initial and following time periods and possibility of method usage in wells with any oil recovery mechanism.
FIELD: testing the nature of borehole walls, formation testing, methods or apparatus for obtaining samples of soil or well fluids, namely downhole tools to determine reservoir parameters.
SUBSTANCE: method involves arranging downhole tool having probe in well bore, wherein the probe comprises at least one executive mechanism for probe extension and retraction; moving the probe to provide probe contact with well wall and accumulating reservoir data. Protective screen is arranged around probe. The protective member may slide between retracted position, where protective member is arranged near body, and extended position, where protective member touches well bore wall, independently of probe.
EFFECT: improved probe and well bore protection, possibility to accumulate data or take samples without erosion.
30 cl, 10 dwg
FIELD: survey of boreholes or wells, particularly measuring temperature or pressure.
SUBSTANCE: device comprises pretest piston to be arranged in flow communication with reservoir, a number of manometers installed in pressure line and valves for selectively supply one of fluid or drilling mud in measuring device. Method involves performing the first test to determine reservoir parameter to be estimated; using the first pretest for the second pretest calculation and obtaining estimated reservoir parameters for reservoir characteristics evaluation.
EFFECT: possibility of reservoir testing device usage to perform measurements at well bottom during predetermined period, decreased land-based system intervention.
36 cl, 27 dwg
FIELD: well survey, particularly to control technical condition of oil well sections over or under hydrostatic well level, as well as of gas well under pressure, by repeated non-contact measurement of infrared well wall surface radiation.
SUBSTANCE: device comprises body, protective optical system window, infrared radiation receiver, modulator, thermostat, infrared radiation chopping frequency stabilizing block, thermostating and thermostabilizing unit, signal amplifying and converting unit, body temperature sensor, electronic body temperature sensor signal amplifying unit; electronic protective window radiation compensation unit. Receiver pickup converts infrared well wall radiation and protective window radiation into electric signal. Contact temperature sensor installed in device body generates electric signal, which is proportional to protective window temperature. Said signal is supplied to electronic body temperature sensor signal amplifying unit and to compensation unit and is mixed with electric signal generated by radiation receiver to compensate signal component defined by protective window radiation in real time so that user registers only electric signal proportional to infrared well wall radiation.
EFFECT: decreased measurement time along with decreased costs.
2 cl, 1 dwg
FIELD: well survey, particularly to determine thermal properties of rock seams surrounding wells during well drilling or cased wells, as well as to detect technical conditions of wells during well operation and downhole equipment operation regimes.
SUBSTANCE: device comprises three identical heat-sensitive sensors arranged along well axis at predetermined locations and adapted to measure the second temperature difference, namely the first, the second and the third ones. Each heat-sensitive sensor includes four identical heat-sensitive resistors constituting heat-sensitive bridges. Heat-sensitive bridge unbalance difference is proportional to the second temperature difference. Unbalance sum is proportional to the first temperature difference. All heat-sensitive resistors are used to measure absolute temperature of probe receiving medium. The first temperature difference depends on constant temperature change along well bore and on local temperature change. The second temperature difference depends only on local temperature change.
EFFECT: increased fullness of temperature field recording and measurement accuracy.
FIELD: well survey, particularly geothermal well survey.
SUBSTANCE: temperature probe assembly comprises temperature sensors installed in upper or lower assembly part and uniformly distributed around a circle having radius r>R3/2, where R3 is probe assembly radius. Circle center coincides with probe assembly axis. Assembly also has safety lamp made as a pipe with orifices. Summary orifice area is not less than pipe cross-sectional area. The probe assembly may be provided with two centralizers arranged in upper and lower parts thereof. In some variants temperature sensor is arranged along assembly axis in upper or lower part thereof, probe assembly has safety lamp made as a pipe with orifices, wherein summary orifice area is not less than pipe cross-sectional area, and pressing device. The pressing device includes two springs arranged in upper and lower probe assembly parts. Temperature sensor is 1-2 mm under or over safety lamp end plane correspondingly. In other variants safety lamp has beveled end and is pressed to pipe string by short generator thereof. Probe assembly variants including temperature sensors and two centrators in upper and lower parts are also disclosed. The temperature sensors are arranged on each spring of upper centrator in upper part thereof or each spring of lower centrator in lower part thereof is provided with one temperature sensor spaced a distance from pipe string or production string axes. The distance is determined from equation. In just other variants probe assembly has centrators arranged in upper and lower parts thereof and temperature sensors carried by substrate formed of resilient material and arranged in lower probe assembly part between springs of lower centrator or in upper probe assembly part between upper centrator springs. Each spring is provided with limiting strip to restrict substrate and temperature sensor displacement with respect to probe assembly axis. Temperature sensors are located in upper or lower probe assembly parts in dependence of downhole instrument movement direction during well survey performance.
EFFECT: increased accuracy of continuous temperature measurement along generator defined by temperature sensor movement due to elimination of liquid mixing in front of temperature sensor.
12 cl, 7 dwg
FIELD: oil and gas industry.
SUBSTANCE: invention is referred to a petroleum industry and can be applied at development of reservoir with a high-viscosity oil or bitumen. It provides efficiency upgrading of warm-up of a bottom-hole zone of a hole, oil viscosity decreasing and increasing of a reservoir oil recovery. Essence of invention: the method includes electric warm-up of a productive strata and bleeding of oil by holes. According to the invention a breaking of electric connection between a part of a casing string in the range of productive strata and other parts of a casing string will be organised in a hole. The tubular annulus between a tubing string and a casing string is space filled by dielectric fluid. Tubing string isolation from down hole equipment, pipe lines on a hole and casing string mouth is organised. An electric contact between a tubing string and a casing string in the range of productive strata is provided. An electric current is fed to a tubing string.
EFFECT: efficiency upgrading of warm-up of a bottom-hole zone of a hole, oil viscosity decreasing and increasing of a reservoir oil recovery.
2 cl, 3 ex
FIELD: oil and gas industry; methods and systems for producing carbohydrates (CH).
SUBSTANCE: system, capable to heat at least part of CH pool, contains heater, which can be placed in bed borehole and retrieved to transfer heat from heater to bed with purpose of thermal decomposition. Heater presents type of electric conductor inside tube, which can be installed and/or removed from open or uncased segment with use of coil or installation/removal system with reeled pipes. At the same time, heater can be used at least in one more alternative open or uncased borehole segment in bed.
EFFECT: productivity efficiency and reliability are increased; cost of heating method and system is reduced.
20 cl, 18 dwg
FIELD: oil and gas production, particularly to prevent damage of oil, gas and injection well casing pipes during well conservation and killing in permafrost rock zones.
SUBSTANCE: method involves arranging hydrosandblast perforator inside casing pipe at permafrost rock location site and cutting casing pipe walls; arranging isolation cement bridges in area of outer casing pipe surface contact with upper and lower permafrost rock zone boundaries; supplying pressurized highly-viscous liquid, for instance heavy oil, in perforated cavities (channels) beyond casing pipes; removing free water from thawed rock area surrounding well to decrease water content in rock and elimination of ice formation in the case of repeated rock freezing.
EFFECT: elimination of casing pipe crushing in permafrost rock zones, seal failure in temporarily abandoned or killed oil and gas well during secondary freezing of thawed rock.
FIELD: underground well construction and operation, particularly in permafrost zones.
SUBSTANCE: refrigerating straight hole guide comprises cold generator, coaxial inner and outer pipes with heat-insulation shells connected with each other by means of annular lids arranged at ends thereof. Upper annular lid has orifices to receive coolant inlet and outlet pipes. Refrigerating straight hole guide additionally has guiding pipe with the first end lowered to lower annular lid and not supported by the lid. Upper end of guiding pipe is connected to cold generator. Lower end of guiding pipe has coolant flow swirler with designed deviation angle.
EFFECT: increased efficiency of well head zone treatment due to cold air (gas) flow directed in lower annular space part and distributed by jet swirl over annular bottom of straight hole guide along with following flow movement to outlet pipes and outer pipe wall cooling.
FIELD: induction heating devices, particularly to heat downhole liquids, particularly paraffinaceous oil and highly-viscous mixtures directly in wells.
SUBSTANCE: downhole heater is made as cylindrical tubular body oriented in well direction and provided with removable lids connected to tubular body ends. Upper lid of cylindrical tubular body has sealed current lead for electrical cable connection coupling and holder arranged on outer surface thereof. Holder end is flanged flow string coupling adapted to receive fastening bolts and provided with current lead orifices. Conical bush pressed with flow string coupling is arranged from cylindrical tubular body side. One section of flow string suspension means is coaxially arranged inside cylindrical tubular body and has outer surface provided with spaced apart induction cylindrical reels brought to connection cable along the tube. Cross-sectional tube dimensions in heater area may be aligned with flow string suspension tubes for oil transportation from well beyond the heater.
EFFECT: prevention of asphalt-tar-paraffin and hydrate deposit forming in flow strings of production wells developed by natural and artificial lift methods for a long time.
4 cl, 2 dwg, 1 ex
FIELD: oil production, particularly underground and thorough well repair to remove asphalt-tar-paraffin, hydrate and ice plugs in hole annuity and tube space of wells provided with pumping units.
SUBSTANCE: method involves creating through inclined channel in face plate; installing lubricator; lowering heater in hole annuity through lubricator; melting plug and injecting working agent. Ball valve is installed in through inclined channel. Lubricator is retained over the ball valve. Before working agent injection processing liquid is additionally supplied under pressure in hole annuity simultaneously with heater lowering and plug melting up to full plug removal from hole annuity.
EFFECT: increased efficiency of asphalt-tar-paraffin, hydrate and ice elongated plugs removal.
7 cl, 2 ex
FIELD: survey of boreholes or wells, particularly indirect fluid parameter determination to measure oil-water mixture flow parameters, namely flow velocity, temperature and oil-water ratio.
SUBSTANCE: method involves arranging elongated heater in fluid flow so that the heater extends in fluid flow direction; installing heat sensors at opposite sensor ends, wherein heat sensors provide remote data reading and are adapted to measure temperature at interface between front heater surface and fluid flow zone and at interface between rear heater surface and fluid flow zone; calculating temperature difference between heater and fluid flow from above measured temperature values; determining oil-water ratio in fluid flow and fluid flow rate from said pressure difference with the use of mathematical or graphical relationship. Device may have the third heat sensor for temperature measurement at spacing from heater action zone. Different heater variants are also disclosed.
EFFECT: possibility to optimize fluid pumping equipment installation, simplified fluid flow parameter determination inside well.
FIELD: oil production, particularly to create optimal thermal regime in producing oil wells to prevent paraffin-hydrate deposits inside wells.
SUBSTANCE: method involves lowering cable with heating unit in tubing string to depth where well fluid temperature exceeds paraffin-hydrate crystallization initiation temperature, wherein the heating unit includes at least two coaxial parts, namely inner and outer ones; linking heating unit of the cable to controllable power source; providing specific power generation by heating unit along tubing string. One part of heating unit has uniform electric resistance along the full length thereof. At least one section of another heating unit part has electric resistance distributed along length thereof in direct proportion to specific power of elementary heating unit section at depth thereof. Distribution of specific power generated by heating unit along tubing string is determined from analytic formula.
EFFECT: decreased power inputs and increased reliability.
FIELD: oil production, particularly heating, cooling, or insulating arrangements for boreholes or wells, for example for use in permafrost zones.
SUBSTANCE: heater is made as cable line including low-temperature cable and high-temperature, namely heating, cable. High-temperature cable comprises current-conductive cords connected with each other from the first cable end and are insulated to create termination unit. Another heating cable end is connected to power source. Cable line extends outside tubing string or cable is spirally wound around tubing string. Heater also has surface-based measuring-and-control unit made, for instance, as programmable frequency electronic control unit and downhole measuring unit. The downhole measuring unit includes at least one sensor (crystal resonator) to read thermobaric fluid parameters. Above sensors are adapted to convert actual temperature and/or pressure values into frequency and are connected with measuring-and-control unit by means of cable line. The sensors are installed on tubing string body and/or on connection clutch thereof depending upon place of fluid parameter measurement, namely inside tubing string and/or in hole annuity.
EFFECT: increased accuracy and reliability of oil production control due to possibility to control thermal field of the well, increased volume of obtained information concerning fluid state in hole annuity, inside tubing string and on outer tubing string surface along with simplified assemblage and operation.
11 cl, 2 dwg
FIELD: oil production, particularly to recover or increase initial oil output from oil production wells along with prevention of mudding structural net development during well operation, with the use of thermal bottomhole formation zone treatment.
SUBSTANCE: method involves heating casing pipe section in perforation zone up to temperature greatly exceeding boiling temperature of oil fractions; maintaining constant temperature regime characterized by casing pipe wall temperature determined from mathematical correlation; determining heat flux distributed transversely to surface to be heated in reservoir rock heating zone with determined initial rock temperature, wherein stable thermal equilibrium condition is kept. Device for above method realization comprises composite sectional units connected with each other and installed in casing pipe. The casing pipe is used as heating and structural load-bearing member. Device has transport head, converters, installation unit, switching-on mechanism, retaining units and connection flanges. The invention permits to assemble device and to bring it into operation without demounting of main conventional oil production equipment. Device may be installed within perforation zone with the use of winch. The winch comprises electric motor, worm reduction gearbox, two drums with traction bands, differential mechanism, cross-arm with hooks and orientator made of elastic material. Winch for device installation within perforation interval of casing pipe may be used after cross-arm substitution for swab with the purpose of oil bottomhole formation zone cleaning (swabbing).
EFFECT: increased simplicity and convenience along with increased oil output and decreased power inputs, which result in decreased produced oil cost.
4 cl, 5 dwg
FIELD: mining industry.
SUBSTANCE: method includes mounting of packing element at lower limit of upper portion of thermo-isolated tubing pipe. Circulation pipe, performing a function of heat-exchange contour, with diesel fuel as heat carrier and following heat exhaust into atmosphere, is connected at whole length to upper portion of tubing string. Their lowering into well and support on the mouth is performed with displacement of tubing string axis relatively to well axis. Upper end of circulation pipe in summer period is connected to forcing line of heat-exchange plant, in winter period to forcing line of cooling plant. Forced circulation of diesel fuel is performed in upper portion of operation column through circulation pipes with following ascent along ring-shaped space. Mathematical formulae for calculating depth of packing element mounting, circulation pipe diameter, tubing string displacement value and diesel fuel flow are provided.
EFFECT: higher efficiency.