Skid-mounted polymer injection method based on water distribution room

Abstract

According to the skid-mounted polymer injection method based on the water distribution room, a preparation skid and an injection skid are included, the injection skid comprises a polymer injection valve set, and the polymer injection valve set is detachably connected with an injection well through a water distribution room pipeline; the preparation pry injects prepared polymer mother liquor into the injection well through the polymer injection valve group; the problems that due to the fact that an existing skid-mounted polymer injection mode is designed depending on a well area, the ground workload is large, investment is high, the polymer flooding development effect is poor, and reserves outside the well area cannot be considered are effectively solved.

Description

Technical Field

[0001] The present disclosure relates to three types of oil layer polymer injection development modes, specifically a skid-mounted polymer injection mode. Background Art

[0002] The transition zone of Gaotaizi Oilfield, Taibei Development Zone and Xingnan Development Zone in Daqing belongs to the third type of oil layer. The river channel sand is small in scale, with many small layers, thin single layer thickness and low permeability. After long-term water injection development, the current water content level is high and the overall recovery rate is low, but the remaining potential in the oil layer is relatively large. The Gaotaizi local injection and polymerization test carried out in 2004 used the existing well network to inject and polymerize the connected oil layers, achieving good oil increase effects and increasing the recovery rate by more than 10 percentage points, providing a feasible technical means for tapping the potential of narrow river channel sand bodies. However, this injection and polymerization mode is developed in units of well areas. During the development process, the following problems were found: First, there are many water injection wells in each well area, and a well area contains several water distribution rooms, so the injection and polymerization systems built around each water distribution room in the well area are different.

[0003] There is no uniformity, so when injecting polymer, the ground preparation and injection system needs to be personalized, and the ground investment is large. Figure 1 As shown in the figure, all single wells in the water distribution room need to be turned to the injection skid. In addition, due to the different number of injection wells and injection volumes in each well area, many specifications of injection skids are required, and the universality of the injection skid is not strong, resulting in a large amount of ground work and high investment; secondly, if the development is carried out according to the well area injection mode, it is restricted by many factors such as the unit area and number of wells in each well area. Outside the well area, there are still many injection wells that meet the conditions that are not included in the planning arrangement, resulting in partial reserve loss and affecting the polymer flooding effect. Summary of the invention

[0004] In view of this, the present invention provides a skid-mounted polymer injection method based on a water distribution room to solve the problems of the existing skid-mounted polymer injection mode, which is designed based on the well area, resulting in large ground workload, high investment, poor polymer drive development effect and failure to take into account the reserves outside the well area.

[0005] In order to achieve the above-mentioned invention object, the skid-mounted polymer injection method relying on the water distribution room includes a preparation skid and an injection skid, wherein:

[0006] The injection skid comprises a polymer injection valve group, and the polymer injection valve group is detachably connected to the injection well through a water distribution room pipeline;

[0007] The preparation skid injects the prepared polymer mother solution into the injection well through the polymer injection valve group.

[0008] In the present disclosure and possible embodiments, for a water distribution room with 3 or less water injection wells, a single well in the water distribution room area is turned around;

[0009] The turning process is to turn the single well to an adjacent water distribution room where the number of injection wells is greater than 3 for combined injection.

[0010] In the present disclosure and possible embodiments, a single well that crosses into an adjacent water distribution room area is turned around;

[0011] The turning process is to turn the single wells that exist crosswise to the adjacent water distribution room.

[0012] In the present disclosure and possible embodiments, the dispensing skid includes a dispersing device;

[0013] The high-pressure water storage tank in the water distribution room provides the preparation sewage to the dispersion device through the tank. In the dispersion device, the sewage is mixed with the polymer dry powder to form a polymer mother liquor of a set concentration.

[0014] In the present disclosure and possible embodiments, the polymer mother liquor is transported to a maturation tank for maturation, and the polymer mother liquor after maturation is filtered through a coarse filter and a fine filter and then input into the injection skid by a transfer pump.

[0015] In the present disclosure and possible embodiments, the high-pressure water in the water distribution room is used as dilution water, and the injection pump of the injection skid mixes the polymer mother liquor and the dilution water through a static mixer and then injects the mixture into the injection well through the polymer injection valve group.

[0016] The present disclosure has the following beneficial effects:

[0017] The skid-mounted polymer injection method based on the water distribution room disclosed in the present invention can cover most of the wells by developing based on the water distribution room, thus avoiding reserve loss; because a preparation skid and an injection skid are built outside the water distribution room, after the polymer injection is completed, the preparation skid and the injection skid can be removed to inject polymer into the next water distribution room, the skid can be reused, thus avoiding equipment idleness; and in subsequent water flooding and water injection, only the skid-mounted device needs to be removed to resume the original process of water injection, thus reducing the workload; the existing skid-mounted polymer injection mode is effectively solved, which has the problems of large ground workload, high investment, poor polymer flooding development effect, and failure to take into account reserves outside the well area due to its design based on the well area. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0019] Figure 1 It is the skid-mounted polymer injection mode relying on the well area described in the background technology of this disclosure;

[0020] Figure 2 It is a skid-mounted injection mode of the embodiment of the present disclosure in which an injection skid is connected outside the water distribution room;

[0021] Figure 3 It is a skid-mounted injection mode of the embodiment of the present disclosure in which an injection skid is connected outside the water distribution room;

[0022] Figure 4 Schematic diagram of the original polymer flooding planning effect of the embodiment of the present disclosure (the shaded area in the figure is the polymer injectable block);

[0023] Figure 5-1 is a schematic diagram of a water distribution room before optimization according to an embodiment of the present disclosure;

[0024] Figure 5-2 is a schematic diagram of an optimized water distribution room according to an embodiment of the present disclosure;

[0025] Figure 6-1 This is a schematic diagram of a water distribution room area with crossed single wells before optimization according to an embodiment of the present disclosure;

[0026] Figure 6-2 This is a schematic diagram of an optimized water distribution room area with crossed single wells in an embodiment of the present disclosure;

[0027] Figure 7 It is a schematic diagram of the effect of the skid-mounted injection method based on the water distribution room according to an embodiment of the present disclosure (the shaded part in the figure is the injectable part). DETAILED DESCRIPTION

[0028] The present disclosure is described below based on embodiments, but it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand the present disclosure.

[0029] In addition, those skilled in the art should understand that the drawings are provided only to illustrate the purpose, features and advantages of the present disclosure, and the drawings are not actually drawn to scale. At the same time, unless the context clearly requires, the words "include", "comprise" and the like in the entire specification and claims should be interpreted as inclusive rather than exclusive or exhaustive; that is, "including but not limited to" meaning.

[0030] The skid-mounted polymer injection method based on the water distribution room of the present invention is further described in detail through the embodiments of the present disclosure in combination with the accompanying drawings, as follows:

[0031] Step 1: Optimize water distribution room

[0032] Since the number of injection wells in different water distribution rooms is different, the oil layer development of injection wells in the same water distribution room on the plane is also quite different. In order to ensure the injection effect and reduce the ground investment, the water distribution room needs to be optimized, as follows:

[0033] 1) Because the ground investment is high if the water distribution room with a small number of injection wells is injected separately, the embodiment of the present disclosure is designed to merge the water distribution rooms with a small number of injection wells for injection;

[0034] 2) The injection wells that cross between two adjacent water distribution rooms are turned around to maintain the integrity of the water distribution rooms and facilitate geological analysis.

[0035] Step 2: Design of skid-mounted solution

[0036] The disclosed embodiment is designed to build both the preparation skid and the injection skid outside the water distribution room. Figure 2 As shown in the figure, after the injection is completed, these skids can be reused. And in the subsequent water drive, only the skids need to be removed to resume the original process of water injection, which reduces the workload.

[0037] Step 3: Design of the preparation skid and injection skid

[0038] 1) Design principles

[0039] First, we build a skid-mounted device based on the water distribution room, and build a preparation skid and injection skid separately outside the water distribution room. The preparation skid and injection skid are modularly designed, and can meet personalized needs by adding or removing individual equipment; second, we adopt the sewage preparation and dilution injection process, and the preparation and dilution of sewage is provided by the water distribution room. A blower is used for disc-type aeration in the tank to achieve aeration on site. Third, a one-pump-multiple-well injection method is used to ensure the viscosity of the polymer mother liquor and smooth injection.

[0040] 2) Determine the scale

[0041] According to the customary technology in this field, a one-pump-multiple-well process is adopted, and the equipment is designed with reserves in terms of maturation time, preparation concentration, injection pump displacement, and quantity; the needs of high and low preparation quantities are met by increasing or decreasing maturation tanks, injection pumps or adjusting the mother liquor concentration.

[0042] 3) Specific plan

[0043] like Figure 2 and Figure 3 As shown: the preparation skid module mainly includes dry powder tank, water tank, dispersion device, maturation tank, coarse filter, fine filter and transfer pump, etc.

[0044] The injection skid module mainly includes an injection pump, a static mixer and an injection valve group.

[0045] 4) Skid-mounted polymer injection process based on water distribution room

[0046] like Figure 2 and Figure 3As shown: the high-pressure water in the water distribution room is directly stored in the water tank, which provides dilution water to the dispersion device. After mixing with the dry powder, it enters the maturation tank for maturation. After maturation, it is filtered through a coarse filter and a fine filter and then transferred to the injection skid by a transfer pump. The injection skid is provided with mother liquid by the injection pump, and the water distribution room provides dilution water. After mixing in a static mixer, it is pumped into a single well.

[0047] The skid-mounted polymer injection method based on the water distribution room disclosed in the present invention is used to carry out polymer injection development in the old area of ​​Taibei Development Zone, so as to further illustrate the detailed steps and technical effects of the skid-mounted polymer injection method based on the water distribution room disclosed in the present invention, as follows:

[0048] The old area of ​​Taibei Development Zone is located in the south of Xingnan Development Zone, with an oil-bearing area of ​​79.4km 2 , geological reserves of 4078.6×10 4 There are 30 water distribution rooms and 679 oil and water wells in the old Taibei area, including 486 oil wells and 193 water wells.

[0049] If the old area of ​​Taibei Development Zone is developed according to the skid-mounted polymer injection mode based on the well area described in the background technology, Figure 4 As shown, Figure 4 The shaded area in the figure is the injectable area, with geological reserves of only 326.7×10 4 t.

[0050] If the development is carried out according to the skid-mounted injection mode relying on the water distribution well of the present invention, the geological reserves of the old area of ​​Taibei Development Zone are calculated as follows: first, the geological reserves of each water distribution room are calculated separately, and then the geological reserves of each water distribution room are summed up to obtain a total geological reserve of 2838.8×10 4 t, as shown in Table 1:

[0051] Table 1 Statistics of injection wells under the jurisdiction of the water distribution room in Taibei Old District

[0052]

[0053]

[0054] By comparing the geological reserves of the skid-mounted polymer injection mode relying on the well area and the skid-mounted polymer injection mode relying on the water distribution well of the present disclosure, it can be seen that the polymer flooding development effect can be effectively improved according to the method disclosed in the present disclosure. Therefore, the skid-mounted polymer injection development relying on the water distribution well is carried out for the old area of ​​the Taibei Development Zone. The specific process is as follows:

[0055] 1. Water distribution room optimization

[0056] 1. Before optimization, some water distribution rooms have relatively few injection wells, less than or equal to 3. If these water distribution rooms are all developed by injection and aggregation, there will be two problems: first, each water distribution room needs to make ground investment, which is expensive; second, the water distribution rooms are scattered step by step, which makes it difficult to manage production. These injection wells are transferred to the adjacent water distribution rooms to form a water distribution room with a certain number of wells.

[0057] For example, in Table 1, there are two water injection wells in the T5-5# water distribution room, with well numbers 5T49-43 and 5T50-F45; there is one water injection well in the T5-9# water distribution room, with well number 5T53-S41 ( Figure 5-1 ); therefore, it is necessary to optimize the water distribution room of these injection wells.

[0058] like Figure 5-2 As shown, the specific optimization of the water distribution room is to turn the injection wells of the T5-5# water distribution room and the T5-9# water distribution room to the adjacent water distribution room T5-3# to form a water distribution room of a certain scale.

[0059] For the entire block of the old area of ​​Taibei Development Zone, there are 11 injection wells that need to be turned around. The final optimization results are shown in Table 2:

[0060] Table 2 Statistics of water distribution rooms with few injection wells and needing turnaround wells

[0061]

[0062] 2. Before optimization, some water distribution rooms have irregular shapes, which will cause errors in calculating development and evaluating effects. Therefore, these single wells that cross adjacent water distribution rooms are turned around to make the shapes of the water distribution rooms more regular and complete, which is more conducive to analysis.

[0063] like Figure 6-1 As shown in Table 1, the injection well 5T2-27 in the 1-1# water distribution room and the adjacent water distribution room 1-5# are intersected; the injection well 5T4-27 in the 1-2# water distribution room and the adjacent water distribution room 1-5# are intersected. Therefore, it is necessary to optimize the water distribution room for these injection wells.

[0064] like Figure 6-2 As shown, these two injection wells are turned to the 1-5# water distribution room to form a water distribution room with a more regular shape and more complete blocks.

[0065] For the entire block of the old area of ​​Taibei Development Zone, there are 7 injection wells that need to be turned around. The final optimization results are shown in Table 3:

[0066] Table 3 Statistics of cross-turn injection wells

[0067]

[0068] For the old area of ​​Taibei Development Zone, after the above optimization, the number of water distribution rooms was reduced from 30 to 23, and the number of injection wells was reduced from 193 to 163.

[0069] 3. Skid-mounted design

[0070] For the preparation skid module, the first is the design of the dispersion device: in order to save construction investment, only one set of dispersion device is built. The dispersion capacity is determined according to the mother liquor volume designed in the geological plan. The second is the design of the maturation tank: considering transportation and installation, the volume of the maturation tank is determined to be 20m 3 , effective volume is 16m 3 (The effective volume is 80% of the total volume). The aging time is 3 hours, the liquid inlet and outlet time is 2.1 hours, and the preparation volume of a single tank = effective volume × 24 hours / (liquid inlet and outlet time + aging time) = 16 × 24 / (2.1 + 3) = 75.2m 3 / tank. Calculated based on the production of 4 maturation tanks on site, the total maturation capacity is: single tank preparation volume × number of normal operating tanks = 75.2m 3 / tank × 4 tanks = 301m 3 / d.

[0071] For the injection skid module, the injection system is designed with three injection pumps, using a frequency conversion device to operate two and keep one as a spare.

[0072] Heating system design: Electric heating for mother liquid pipeline and clean water pipeline; Electric heating for preparation skid-mounted pump room and injection skid-mounted pump room. Water for preparation and dilution is drawn from high-pressure sewage in the water distribution room.

[0073] 4. Results Analysis

[0074] 1. Improve the effect of polymer flooding development

[0075] like Figure 4 As shown in the figure, the original plan was based on well areas, and only selected wells with continuous and relatively concentrated development (the shaded area in the figure is the injectable area) after comprehensive consideration of economic benefits. Many wells with insufficient development thickness, scattered distribution and no scale were not included in the original plan, resulting in a large loss of reserves. The specific data are: 52 injection wells, 326.7×10 4 t.

[0076] like Figure 7 As shown in the figure, the invention adopts the skid-mounted injection based on the water distribution room, and the injection range is expanded. The injection area (the shaded part in the figure) can reach 98% of the whole area. The number of injection wells increases, the geological reserves increase, and the development effect is better. After implementation, the number of injection wells increased to 163 wells, which is 111 wells more than the original plan; the geological reserves are 2838.8×10 4 t, an increase of 2512.1×104 t.

[0077] 2. Reduce ground investment costs

[0078] (1) Not building a water injection booster skid (including booster equipment and process) saves 1.2 million yuan;

[0079] (2) Turnaround costs: saving RMB 333.0-40.5=292.5 million.

[0080] First, the optimization plan turns around 18 wells, and the investment is: 750 meters × 18 wells × 300,000 yuan / km = 405,000 yuan; second, the original plan requires the construction of new single-well pipelines, and the investment is: 750 meters × 148 wells × 300,000 yuan / km = 3.33 million yuan;

[0081] In summary, the skid-mounted injection mode based on the water distribution room disclosed in the present invention can save a total investment of 4.125 million yuan.

[0082] The above-described embodiments are only embodiments of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present disclosure. It should be noted that, for a person of ordinary skill in the art, without departing from the concept of the present disclosure, several variations, equivalent substitutions, improvements, etc. may be made, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the attached claims.

Claims

1. A skid-mounted polymer injection method based on a water distribution room, comprising a preparation skid and an injection skid, characterized in that: The injection skid comprises a polymer injection valve group, and the polymer injection valve group is detachably connected to the injection well through a water distribution room pipeline; The preparation skid injects the prepared polymer mother solution into the injection well through the polymer injection valve group.

2. The skid-mounted polymer injection method based on the water distribution room according to claim 1 is characterized in that: For water distribution rooms with 3 or fewer injection wells, turn around the single wells in the water distribution room area; The turning process is to turn the single well to an adjacent water distribution room where the number of injection wells is greater than 3 for combined injection.

3. The skid-mounted polymer injection method based on a water distribution room according to claim 1 or 2, characterized in that: For single wells that cross in adjacent water distribution areas, turn around; The turning process is to turn the single wells that exist crosswise to the adjacent water distribution room.

4. The skid-mounted polymer injection method based on the water distribution room according to claim 3 is characterized in that: The dispensing skid includes a dispersing device; The high-pressure water storage tank in the water distribution room provides the preparation sewage to the dispersion device through the tank. In the dispersion device, the sewage is mixed with the polymer dry powder to form a polymer mother liquor of a set concentration.

5. The skid-mounted polymer injection method based on the water distribution room according to claim 4 is characterized in that: The polymer mother liquor is transported to a maturation tank for maturation. The polymer mother liquor after maturation is filtered through a coarse filter and a fine filter and then transported to the injection skid through a transfer pump.

6. The skid-mounted polymer injection method based on the water distribution room according to claim 5 is characterized in that: The high-pressure water in the water distribution room is used as dilution water, and the injection pump of the injection skid mixes the polymer mother liquor and the dilution water through a static mixer and then injects the mixture into the injection well through the polymer injection valve group.

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