RU2380523C1 - Multi-reservoir oil field development method - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: method includes reservoirs subdivision by groups with different filtration capacity properties, selecting reservoir groups with a different permeability, pumping in a working agent through injection wells, oil withdrawal through production wells. After reservoir subdivision according to their filtration capacity properties, divide them on three groups of a different permeability using parkers. Selectively separate lower reservoir group in injection wells, execute additional permeability examination of the top and bottom groups according to corresponding separated columns. Then remove sealing, study total permeability of the middle and the bottom reservoirs groups. Equip the injection wells bottom parkers with flow separators, for example with a nozzle or a control valve. Then pump in the working agent along the separate columns in to the top reservoir group and into a middle and bottom reservoir groups. At that execute pumping on the wellhead with one injection line, separate it with a flow regulator, for example with valves for the separate columns of every injection well. Execute the reservoir group product withdrawal simultaneously or separately in dependence with the product physical-chemical properties.

EFFECT: method capabilities extension, simplification and cost cutting of production process.

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Description

The invention relates to the oil industry, namely the development of a multilayer reservoir with heterogeneous permeability formations.

The well-known "Method for the development of a multilayer oil reservoir" (patent RU No. 2132939, ЕВВ 43/20, publ. Bull. No. 22 of 07/10/1999.), including an assessment of the average values of reservoir properties of the reservoirs, the selection of oil from the reservoirs through production wells, water injection in a cyclic mode through injection wells, injection of an agent that increases the hydrodynamic resistance of the formation, characterized in that the layers are divided into two groups, and their average values of the filtration-capacitive properties are estimated for each group, with the first g the group includes reservoirs with higher permeability and faster development of reserves, the second group includes less permeable reservoirs with slower development of reserves, and an agent that increases the hydrodynamic resistance of the formation is pumped into at least one injection and / or production well and in the second half of the period of decrease in reservoir pressure, while the duration of the water injection cycle is selected from the condition of ensuring the smallest difference in the averaged speeds of displacement of the displacement fronts in the reservoirs productive section of the first and second groups.

The disadvantages of this method are the difficulty of use, since constant monitoring and injection of reagents is required, which in turn leads to high material costs, the narrowness of the field of application in multilayer fields discovered by each of the wells, since groups with the same filtration-capacitance are rare in practice properties grouped in the upper and lower cavities of the well, separated by a packer, and two injection lines are required for injection into different-permeable groups of formations.

The closest in technical essence and the achieved result is the "Method for the development of a multilayer oil reservoir" (patent RU No. 2314414, ЕВВ 43/20, publ. Bull. No. 1 dated 01/10/2008), including the separation of reservoirs into two groups with different reservoir properties, the allocation of the first group of formations with higher permeability and the second group of formations with lower permeability, injection of a working agent through injection wells, oil selection from the formations through production wells, characterized in that in the second group of formations with with a lower permeability, an operational object with a hydrophobic rock surface is isolated, micellar solution rims are pumped into it, which are successively displaced by buffer fluid rims and previously purified commercial or Cenomanian water; purified bottom-product or Cenomanian water in the first group of reservoirs with higher permeability, and the selection of oil is carried out simultaneously from all groups of layers.

The disadvantages of this method are the difficulty of use, since constant monitoring and injection of reagents is required, which in turn leads to high material costs, the narrowness of the field of application in multilayer fields discovered by each of the wells, since groups with the same filtration-capacitance are rare in practice properties grouped in the upper and lower cavities of the well, separated by a packer, and two injection lines are required for injection into different-permeable groups of formations.

The technical task of the proposed method is to expand the functionality by dividing into three groups of formations with the same filtration-capacitive properties, simplifying and cheapening the development of a multilayer field by eliminating the need to treat some formations with reagents and using one injection line to pump a working agent into groups of formations.

The technical problem is solved by the method of developing a multilayer oil reservoir, including the separation of formations into groups with different filtration-capacitive properties, the allocation of groups of formations with different permeabilities, the injection of a working agent through injection wells, the selection of oil from the formations through production wells.

What is new is that after separation of the reservoirs by filtration-capacitive properties, they are divided into three groups with different permeabilities using packers, after which the lower group of reservoirs is selectively cut off in the injection wells, the upper and lower groups are additionally examined for the permeability of the reservoirs by the corresponding separate columns, remove the insulation, study the total permeability of the middle and lower groups of reservoirs, on the basis of this, the lower packers of injection wells are equipped with a flow separator, for example, a nozzle and and a control valve, and the working agent is injected in separate columns into the upper group of formations and into the middle and lower groups of formations, while at the mouth, injection is performed from one injection line, broken by wellhead flow controllers, for example, valves, for individual columns of each injection well, moreover, the rise of formation products from producing wells is carried out simultaneously or separately, depending on the physicochemical properties of the formation products.

Figure 1 shows a diagram of the implementation of the method in the injection well.

Figure 2 shows a diagram of the implementation of the method at the mouth of the injection well.

A method for developing a multilayer oil reservoir in well 1 (see FIG. 1) includes dividing the strata into three groups with different reservoir properties: upper 2, middle 3 and lower 4; the separation from above of these groups of 2, 3 and 4 layers with different permeabilities by the corresponding packers 5, 6 and 7. Moreover, first, in the injection well 1, the lower packer 7 with the passage channel 8 and the liner 9 is installed, then the middle packer 6 with the passage channel 10, large, than the passage channel 8 of the lower packer 7, and then on the pipe string 11 the upper packer 5 with an internal passage diameter 12 larger than the passage channel 10 of the middle packer 6. Next, the process string 13 is lowered into the pipe string 11 with the nipple 14 at the end interacting airtight surface at the end of the descent with the passage channel 10 of the middle packer 6. Then selectively on several injection wells 1 into the production string 13 on the rope (not shown in figure 1) with a plug (not shown in figure 1), which hermetically closes the passage channel 8 of the lower packer 7, cutting off the lower group of formations 4. Then, a working agent is injected into the upper 2 and middle 3 groups of formations, respectively, through the pipe string 11 and process column 13, studying the permeability of these groups of formations 2 and 3. Then, the plug is removed from the well 1 and injected through the production string 13 into the middle 3 and lower 4 groups of formations, studying their total permeability and determining the permeability of the lower group of formations 4. Based on this study, in all injection wells 1, on a rope (not shown in FIG. 1) through the production string 13 lower the flow separator 15 inserted into the passage channel 8 of the lower packer 7. In practice, a nozzle with a calibrated flow diameter for proportional flow separation or a control valve configured Fired to reduce the discharge pressure under the lower packer 4 by 1-5 MPa. After removing the rope without the flow separator 15 from the well, the working agent is pumped through the pipe string 11 and the production string 13 under the necessary pressure, respectively, into the upper group of formations 2 and middle 3, and the lower 4 group of formations through a flow splitter 15. At the same time, at the mouth 16 (see figure 2) the injection is carried out from one injection line 17, breaking the wellhead flow controllers 18 and 19 for the columns 11 (see figure 1) and 13, respectively, on each injection well 1. As wellhead flow controllers 18 ( see figure 2) and 19 in practice used There are valves, fittings with different through-holes and valve assemblies configured for a corresponding pressure drop. In this case, the rise in the production of groups of formations 2, 3 and 4 from production wells (not shown in Fig.) Is carried out simultaneously by one or more pumps, equipping, for example, passage channels 8 (see Fig. 1) and 10 corresponding to the middle 6 and lower 7 packers with fittings with calibrated holes, or separately, using alternate production with cutting off unused groups of layers or on independent pipe columns depending on the physicochemical properties of the products of the layers. This depends, for example, on the presence of sulfur in one of the groups of formations 2, 3 or 4, but not in others, then the products of a group of 2, 3 or 4 formations with sulfur are mined from a separate pipe string (not shown in Fig.), And the rest in total. Moreover, the author does not claim to methods for simultaneous or separate operation of producing wells.

Since on the territory of the Russian Federation (RF) groups of formations with three different filtration-reservoir properties of formations are found 2-3 times more often than with two, the proposed method is functionally more in demand, while it is simple and cheap to use, since it does not require leveling the waterflooding front of the injection of reagents and uses one injection line to pump the working agent into all groups of formations.

Claims (1)

A method for developing a multilayer oil reservoir, including dividing the strata into groups with different filtration-capacitive properties, isolating stratum groups with different permeabilities, injecting a working agent through injection wells, extracting oil from the strata through production wells, characterized in that after separating the strata by filtration capacitive properties they are divided into three groups with different permeability using packers, and then selectively in the injection wells cut off the lower group of reservoir , the upper and lower groups for the corresponding separate columns are additionally examined for formation permeability, isolation is removed, the total permeability of the middle and lower groups of reservoirs is studied, based on this, the lower packers of injection wells are equipped with a flow separator, for example, a nozzle or a control valve, and the working agent is injected individual columns in the upper group of layers and in the middle and lower groups of layers, while at the mouth injection is made from one injection line, breaking the wellhead regulator and flow, such valves for the individual columns of each of the injection well, wherein the lifting formations of the product groups of production wells produce, simultaneously or separately, depending on the physico-chemical properties of these groups of products formations.

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