The way to develop low-permeability oil and gas or gascondensate-oil system horizontal and inclined wells
The invention relates to the oil and gas industry and may find application in the development of tight oil and gas or gascondensate-oil deposits, in particular, their oil rims. The objective of the invention is to increase the flow rate of oil wells in low-permeability reservoirs. The inventive low-permeability oil and gas or gascondensate-oil reservoir develop a system of horizontal and inclined wells for oil extraction. Thus have the perforation interval of these wells in pure oil zone, and also in the field of oil and gas contact when the distance to the contact 0-5 m 1 PL., 2 Il.
The invention relates to the oil and gas industry and may find application in the development of tight oil and gas or gascondensate-oil deposits, in particular, their oil rims.
There is a method of extracting oil from podgotovki zone oil and gas reservoirs in the system producing horizontal and/or vertical wells, the relationship between the production well carried out on sections of an oil rim with a relatively high filtration seprately he is in low-permeability reservoirs, reduces oil production. Reduced oil production and productivity of wells for oil.
The closest in technical essence of the present invention is a method of developing oil and gas or gascondensate-oil system horizontally-inclined of wells, their location bottom of perforation interval in podgotovki area and selection of oil . The upper perforation interval wells placed below the gas-oil contact (GOC) on 6 or more meters of the Development are in the mode of maintaining the current reservoir pressure by injection of the working agent is water.
The known method can be used in high-permeability reservoirs, and in low-permeability reservoirs, it leads to a lower production rate and productivity of wells for oil.
The invention solves the problem of increasing production of oil wells in low-permeability reservoirs.
The task is solved in that in the known method the development of low-permeability oil and gas or gascondensate-oil system horizontal / directional wells with the location of the bottom of the perforated interval in podgotovki area and the selection of oil, according to the invention the upper perforation interval horizontally-Natacha.
The essential features of the method are:
1. Development of low-permeability oil and gas or gascondensate-oil system horizontal directional wells.
2. The location of the bottom of perforation interval horizontal and inclined wells in podgotovki zone.
3. The selection of oil.
4. Placing the top of the perforated interval horizontal and inclined wells in pure oil zone.
5. Placing the bottom of perforation interval horizontal and inclined wells in the area of gas-oil contacts.
Signs 1-3 are common with the prototype of the essential features and characteristics 4, 5 - distinctive essential features of the invention.
In the known technical solutions in the development of oil and gas and gascondensate-oil deposits horizontally-inclined wells with the location of the bottom of the perforated interval in podgotovki zone oil zone below the gas cap), in high-permeability reservoirs of gas is far ahead of the oil, gas breakout occurs with a significant decrease in oil production rate. The problem of increasing production wells solve by removing the top of the perforated interval of the wells at a distance of 6 m and the battle deposits to reduce breakthrough gas and thereby increase the flow rate of oil.
During the development of low-permeability oil and gas or gascondensate-oil deposits, this solution is not acceptable. Therefore, the proposed technical solution, using a well-known fact a significant impact on the oil production, gas-liquid factor and utilization wells, placement of the working part (perforation) of the wells with respect to the STC, respectively, the upper perforation interval horizontal and inclined wells placed in pure oil zone, and the lower interval is placed in the STC region. During the development of deposits on the mode of gas repression lower perforation interval support at the level of the STC, for example, by isolating the bottom of the perforated interval of the well exposed above the STC. It is known that the extraction of oil from low-permeability reservoirs reservoir pressure in this well is declining rapidly. When placing the bottom of the perforated interval in the region of the STC gas from the gas cap, when in the well, will be partially dissolved in the oil, increasing its volume, and thereby contribute to raising the pressure. The upper perforation interval feature in pure oil zone (the zone above which is not the gas cap, there is no STC, i.e., in the oil rim).
Accommodation n the wells will be significantly lower than on the former location of the bottom of the perforated interval in the region of the STC, and the top of the perforated interval in pure oil zone.
The development of deposits are to maintain reservoir pressure by injection of working agent (water, gas) or gas mode repression.
As a result, the flow rate is increased by 50% or more.
The invention is illustrated by drawings, where:
in Fig.1 shows a section of oil and gas deposits, developed by maintaining reservoir pressure horizontally-inclined borehole at the location of the top of the perforated interval in pure oil zone and the bottom of the perforated interval in the region of the STC and injection wells;
in Fig.2 - cut the oil and gas deposits under the regime of the gas repression horizontally-inclined well.
The method is as follows.
The development of low-permeability oil and gas or gascondensate-oil deposits carry out a system of horizontal and inclined wells. While their lower perforation interval feature in the field of STC podgotovki zone, and the upper perforation interval in pure oil zone. The development of deposits carried out by maintaining reservoir pressure by secac the/p>
The oil under the effect of reservoir pressure is supplied to the horizontally inclined hole, and the gas flowing through the lower perforation interval of the gas cap, plays the role of the internal gas and contributes to the rise of oil. During the development of deposits on the mode of gas repression varies the position of the STC (reducing the STC during the expansion of the gas cap).
Is the projection of the bottom of perforation interval over STC. In order to maintain the specified spacing of the perforations in the region of the STC, move it around in the STC region, for example, by isolating the bottom of the perforated interval of the well exposed above the STC. The selection of oil passes through horizontally-inclined well.
Examples of specific performance
As an example, the data on oil production from the Eastern Block of the Orenburg field
Average depth, m 1800-1950.
Average net gas pay thickness is 25 m
The average saturated thickness is 105 meters
Porosity, D. E. - 0,08-0,12.
The average saturation, D.% - 0,75-0,85.
Permeability, 10-3μm2- 0,005-0,015.
Reservoir temperature, °C - 37.
Reservoir pressure, MPa - 21,4.
Oil viscosity at reservoir conditions, MPa.with - 0,44.
Platnost is their oil, m3/t - 150.
Horizontal wells 5.2 drilled at the site of the Eastern Block of the Orenburg field. Well 5.2 has an upper perforation interval in pure oil zone, and the lower perforation interval is podgotovki zone in the region of the STC. Well 5.2 works with a rate of 44 tonnes.
Horizontally-inclined well 4.3 drilled on the same section of the Eastern Block of the Orenburg field. It has an upper perforation interval in pure oil zone, and the lower perforation interval is podgotovki the area below the STC 25 m Bore 4.3 works with a rate of 22 t/day.
Thus, the flow rate 5.2 in example 1 (the proposed solution) is two times higher than wells 4.3 example 2.
As a result, the oil production rate horizontal and inclined wells on the proposed technical solution is increased by 50% or more.
Sources of information
1. Baturin Y. E., Bogdanov, C. L., Degtyaryov E. A., Medvedev N. I., Sarkisyants B. R., George, A. N. The way to develop complex oil with a thin oil rim. RF patent 95116013/03.
2. Analysis of the results of the drilling and operation of horizontal wells shareholdings field. The “Oil industry”, No. 8, 2000nter; margin-top:2mm;">Claims
The way to develop low-permeability oil and gas or gascondensate-oil system horizontal / directional wells for oil extraction, including the location of the perforation interval in pure oil zone, and gas-oil contacts when the distance to gas-oil contacts 0-5 m
FIELD: oil and gas production.
SUBSTANCE: groups of high intake- and low intake-capacity injecting wells are chosen in a single hydrodynamic system and, for each well, oil reservoir properties and permissible degree of pollution of fluid received by high intake-capacity wells are determined. When fluid from low-permeable oil reservoir flows off through high intake-capacity wells, this fluid is cleaned to permissible degree of pollution.
EFFECT: reduced losses in intake capacity of formations and increased time between treatments of wells.
FIELD: oil and gas extractive industry.
SUBSTANCE: method includes construction of wells and oil and gas collection system, forcing water from water-bearing level into oil deposits, flow of oil from oil deposits into secondary deposit and following extraction of oil from secondary deposit for useful implementation. Resources of deposit are separated on basis of natural energy characteristic on screened and having rigid water-forcing mode. Deposit is operated by three well types. Of the latter flow wells connect oil deposits to secondary deposit for flowing and collection of oil in upper bed under effect from gravitation. Balancing wells connect screened deposits and secondary deposit to water-forcing level for balancing of bed pressures and preventing loss of rocks stability. Extraction wells connect secondary deposit to oil and gas collection system. Selection of bed for secondary deposit is performed from number of highly penetrable beds, having maximally allowed excess over oil deposits.
EFFECT: higher oil yield, higher effectiveness.
5 cl, 3 dwg
FIELD: oil extractive industry.
SUBSTANCE: method includes drilling of deposit according to row-wise non-even grid of wells with distance from force to extractive rows, greater than distance between extractive rows, pumping of displacing gent into force wells, extraction of product from product wells and transferring of displacing agent pumping front to extraction area. According to invention, transferring of displacing agent pumping front to extraction area is performed by drilling side horizontal shafts in all wells of force row and directed towards extractive row by beds ad zones with most remainder oil saturation level. Then among these wells are singled out, horizontal shafts of which pass along beds and areas with lesser oil saturation level. Pumping of displacing agent is restarted, and other wells are transferred to product category. These wells are operated with face pressures lower than saturation pressure until reaching 98% water saturation level. After that pumping of displacing agent is restarted along all other wells of force row. During that, rows of extractive wells are operated in normal mode.
EFFECT: higher efficiency.
FIELD: oil industry.
SUBSTANCE: according to first variant of method, force and product wells are drilled, working agent is fed through force wells, oil is extracted through product wells, dome-like raised portions are marked out, which surpass absolute marks of bed, additional wells are positioned in these portions. Wells placement is planned at tops of dome-like raised portions even with breach of evenness of planned well mesh. After full drilling of wells mesh and in case of more accurate definition according to data of drilled wells of deposit of dome-like portions side shafts are drilled from adjacent wells towards more precisely defined tops of dome-like portions, controlling the deposit. In adjacent wells and side shafts, positioned on tops of dome-like raised portions , range of productive bed is opened between absolute mark of ceiling in this well and absolute mark, appropriate for ceiling in closest well. According to second variant of method practically analogical operations are realized as in first variant, except when absolute mark of ceiling of productive bed according to adjacent wells is lower than mark of sole of productive bed, whole bed is opened in side shafts.
EFFECT: higher efficiency.
2 cl, 2 dwg
FIELD: oil reservoir development, particularly for developing water-flooded ones.
SUBSTANCE: method involves withdrawing oil through production wells and ejecting working substance through ejection wells. To prevent water ingress from well bore into oil-saturated formation area formation is perforated in water-oil interface zone so that lower part of oil-saturation formation interval and upper part of water-flooded formation interval are penetrated. This provides oil relative permeability retention in oil-saturated formation area. To prevent formation mudding during initial perforation thereof drilling is performed in depression, balance and repression modes with pressure of not more than 3 MPa. As far as oil is depleted perforation interval is extended towards oil-saturated formation area.
EFFECT: possibility to retain oil relative permeability of oil-saturated formation area.
2 cl, 2 dwg
FIELD: oil field development, particularly for ones with nonuniform reservoirs.
SUBSTANCE: method involves drilling injection and production wells; flooding oil reservoir and extracting oil out of well; defining more exactly geologic aspects on the base of drilling results; designing and drilling additional wells with horizontal bores or drilling horizontal bores from existent wells; determining location of reservoir drive zone boundaries; calculating volume of dead oil located near drive zones; drilling horizontal bores from existent wells located near drive zones and/or new wells with horizontal bores located in above zone, wherein horizontal bores are drilled in direction perpendicular to drive zone boundaries.
EFFECT: improved oil recovery.
2 dwg, 1 ex
FIELD: oil industry.
SUBSTANCE: method includes drilling vertical product and force wells, extracting oil from product wells, forcing working agent through force wells, making side horizontal shafts in force wells, forcing working agent through side horizontal shafts of force wells. Additionally, side horizontal shafts are made in extraction wells. Oil is taken through side horizontal shafts of extractive wells. With pressure in the well, decreased for 5-10% from hydrostatic pressure, all side horizontal shafts are made by washing away rock under pressure of fluid of around 15-20 mPa. Direction of all side horizontal shafts is set to be parallel to rows of wells.
EFFECT: higher oil yield.
1 ex, 1 dwg
FIELD: oil production industry, particularly enhanced recovery methods for obtaining hydrocarbons.
SUBSTANCE: method involves drilling production and injection wells and maintaining formation pressure; performing seismic works to determine volumetric routing of natural macrocrack system with lateral and depth routing; forming production and injection macrocracks of above system; drilling wells to corresponding macrocracks and forming producing well-macrocrack systems for oil production and injection well-macrocrack for formation flooding or production well-macrocrack for oil production and system including vertical and/or horizontal multibranch wells for formation flooding or injection well-macrocrack system for formation flooding and system including vertical and/or horizontal multibranch production wells for oil production or production well-macrocrack system, injection well-macrocrack system and system including vertical and/or horizontal multibranch production and injection wells.
EFFECT: increased efficiency, oil recovery and production well injectivity, as well as increased sweep efficiency and oil recovery ratio.
FIELD: oil production industry, particularly oil deposit development.
SUBSTANCE: method involves pumping working agent, namely water, in two stages. The first stage is performed with the use of power pumps. The second one is carried out by means of hydraulic measuring pumps, which are used to convert injection pressure created by power pumps. If it is necessary to increase pressure in water lines used to deliver water to separate injection wells pressure is regulated in accordance with necessary water volume to be injected in wells on the base of collecting properties of oil formations in bottomhole formation zones. This is performed by providing change in pump piston diameter and stroke ratios in the first and the second sections of hydraulic measuring pumps, which are selected on the base of hydraulic resistance variation depending on water flow velocity. Parameters characterizing injection system operation are simultaneously measured and efficiency of the method and equipment operation is detected from above characteristics.
EFFECT: increased efficiency of oil bed development due to energy-saving equipment and technique usage for formation pressure maintaining.
2 cl, 2 dwg
FIELD: enhanced recovery methods for obtaining hydrocarbons.
SUBSTANCE: method involves flooding production bed through injection wells with the use of pump units. In the case of terrigenous porous productive bed flooding acoustical sound resonators with resonance frequency setting are installed in injection line. This eliminates amplitude of alternating low-frequency liquid pulsation sound generated by pump units. Method also involves providing constant compression mode in productive beds and frontal oil drive from productive bed.
EFFECT: increased operational reliability.
1 ex, 3 dwg