The way to develop heterogeneous permeability oil reservoirs
The invention relates to the field of the oil industry, and in particular to methods of development of oil fields with heterogeneous permeability layers using physico-chemical methods of enhanced oil recovery. Improves the efficiency of the development of layered heterogeneous permeability oil reservoirs with the use of aqueous polymer solutions. The inventive method includes dual injection through injection wells rims of the polymer solution, followed by displacement of water. The interlayer is less permeability is taken for the base. The polymer is not obtained. The volume and viscosity of polymer solutions injected into the other layers, select from the clearing conditions fluid flow resistance so that the moment of their approach to the production wells coincided with the moment of the approach of the displacement front in the underlying interlayer. Volumes rims and viscosity of polymer solutions injected into the other layers, determine the rate of change of speed of movement of the displacement fronts in each of the layers so that their fronts are suited to the production wells simultaneously with the displacement front in the base group relates to the field of oil industry, namely, the way of the development of oil fields with heterogeneous permeability layers using physico-chemical methods of enhanced oil recovery.There is a method of designing heterogeneous permeability oil reservoirs, which consists in injecting into the reservoir an aqueous solution of polymer with high viscosity [M. L. Surguchev Secondary and tertiary methods of enhanced oil recovery". M.: Nedra, 1985, pp. 165-175].At the displacement front is reduced viscous instability, and when pumping through a single filter, the volume of the rim is distributed in layers in proportion to their pickup. Larger volume enters the high permeability layers and largely increases the filtration resistance that ultimately, it is believed, leads to the alignment of the displacement front and expanding reservoir flooding. On the basis of experimental data optimal amount rims considered to be in the range of 0.2-0.3 of the pore volume of the reservoir when the weight of the polymer concentration of 0.05%.The disadvantage of this method is often premature water breakthrough through highly permeable interlayer, when the viscosity of the solution and resistance factor becomes plastome high permeability, which consists in injecting into the reservoir an aqueous solution of the polymer with the addition of the thickener [A. S. USSR 1837104, IPC6E 21 IN 43/20]. This way you can prevent premature breakthrough of injected water in highly permeable interlayers.The disadvantage of these methods is that viscous solutions of polymers substantially block the low permeability layers.The prototype is the way to develop heterogeneous permeability oil reservoirs, which is dual injection through injection wells rims of polymer solutions followed by pushing them with water. In high-permeability layers inject solutions of polymers of high molecular weight and low-permeability layers - solutions of polymers of low molecular weight with respect to the conditions that the average size of the macromolecules of the polymer injected into the interlayers, was less than the average diameter of the pore channels [RF patent 2095555, IPC6E 21 IN 43/22].The disadvantage of the prototype is that the injection of the polymer solution even low molecular weight in the low permeability layers reduces the rate of oil production from the formation, thereby reducing the overall rate of production.NEA for high-permeability layers. This leads to increased consumption of reagents, and the overall pace of development is reduced.The present invention aims at improving the efficiency of the development of layered heterogeneous permeability oil reservoirs with the use of aqueous polymer solutions.The result is achieved that the way to develop heterogeneous permeability oil reservoirs, including dual injection through injection wells rims of the polymer solution, followed by displacement of water, the formation of lower permeability are taking over the base, in which the polymer is not obtained, and the volume and viscosity of polymer solutions injected into the other layers, select from the clearing conditions fluid flow resistance so that the moment of their approach to the production wells coincided with the time coincided with the moment of the approach of the displacement front in the underlying interlayer, with the amounts of rims and viscosity of polymer solutions injected into the other layers, determine the rate of change of speed of movement of the displacement fronts in each of the layers so that their fronts are suited to the production wells simultaneously with the displacement front in the underlying interlayer in a particular GE the thieves type and concentration of the polymer is determined on the basis of the data on its rheological and filtration characteristics, obtained on core samples extracted from the interlayers.The method is as follows. For the selected area oil fields, presents a layered-inhomogeneous layer on the core samples previously examined their filtration characteristics. In accordance with the reserves and profitability generation choose the seams with low permeability, which take over the base. Then estimated by taking into account the state of development at specific geo-physical conditions determine the necessary changes in fluid flow resistance of the high-permeability layers of the conditions concurrent with the deposition of the interlayer approach fronts displacement to the production wells. From the obtained characteristics of the movement as a first approximation to determine the minimum volume of the rims so that between the front and rear edges of the rims of similar interlayers do not have any gap. Having volumes rims, choose the types of polymers on their rheological characteristics so that the flow of polymer from the high permeability of the formation in the less permeable was the most difficult due to the abrupt change of the resistance factor. Having volumes of fringes in the second approximation, the s method were tested in a model of layered heterogeneous reservoir. The model is made of transparent material, its length 1.6 m, height of 0.36 m, width 0,035 m Porous medium - ground quartz sand. The reservoir was modeled three hydrodynamically linked layers with a thickness of 0.12 m, the Permeability of the low permeability of the formation of 0.4-0.5 μm2and high permeability is from 1.2 to 2 μm2. The deposition of the interlayer was sandwiched between highly permeable. Used polymer Accutrol-623 (M=5106). As a solvent for polymers and for eviction was used tap water. As the oil used oil horizon D1Romashkinskoye field. The displacement of the primary. Displacing water and polymer solutions were pumped into the reservoir from separate containers in each interlayer, the selection of fluid produced from each of the interlayer. The movement of the fronts of the displacement was controlled visually by the introduction of the color indicator. The results of the experiments are shown in the table.The experiments showed that injection of a solution Accutrol-623 volume of 0.3 of the total pore volume of the reservoir in the deposition of the interlayer pumped smaller part of the whole solution mainly injected into the high permeability layers. However, even a small about what byte 2 in the deposition of the interlayer polymer is pumped. In high-permeability layers it took to upload rims from 0.1 pore volume of the reservoir, the rate of production in comparison with experiment 1 increased 1.6 times and was obtained self-similar mode of movement of the displacement fronts. Due to the increase in coverage has increased anhydrous development and ultimate oil recovery.
Claims1. The way to develop heterogeneous permeability oil reservoirs, including dual injection through injection wells rims of the polymer solution, followed by displacement of water, characterized in that the interlayer is less permeability is taken for the base, in which the polymer is not obtained, and the volume and viscosity of polymer solutions injected into the other layers, select from the clearing conditions fluid flow resistance so that the moment of their approach to the production wells coincided with the moment of the approach of the displacement front in the underlying interlayer, with the amounts of rims and viscosity of polymer solutions injected into the other layers, determine the rate of change of speed of movement of the displacement fronts in each of the layers so that their fronts are suited to the production wells at the same time sychosis fact, to provide the desired viscosity of the solution, the type and concentration of polymer is determined on the basis of the data on its rheological and filtration characteristics obtained on core samples extracted from the interlayers.
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