Method and device for calculating safe injection pressure of high-position water injection, equipment and medium

Abstract

The invention relates to a calculation method and device for high-position water injection safety injection pressure, equipment and a medium, in particular to the field of water injection development of an anticline oil reservoir with a gas cap. The calculation method comprises the steps that the pressure of the reservoir top structure depth is calculated by integrating the stratum fracture pressure gradient, the gas cap zone stratum pressure gradient, the reservoir gas-oil interface depth, the reservoir top structure depth and the stratum depth where the water injection well close to the high position of the gas cap zone is located; and according to a safe injection pressure standard that the reservoir top structure depth pressure does not exceed 80% of the stratum fracture pressure of the depth, the maximum safe injection pressure of the well bottom of the water injection well close to the high part of the gas cap area is calculated. According to the calculation method provided by the invention, accurate confirmation of the maximum safe well bottom injection pressure of the water injection well close to the high part of the gas cap area is realized, a foundation is laid for optimization of an injection-production system and optimization of an injection-production well number ratio, and improvement of an oilfield development effect is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of water injection development of anticline oil reservoirs with gas caps, and specifically to a method and device, equipment and medium for calculating the safe injection pressure of high-position water injection, and especially to a method and device, equipment and medium for calculating the safe injection pressure of high-position water injection wells adjacent to gas cap areas by taking into account the gas cap pressure transmission and oil and gas pressure gradient differences. Background Art

[0002] At present, the injection pressure of water injection wells is an important development indicator in the process of oil field development and production. Although in some cases increasing the injection pressure is beneficial to increasing the water injection intensity, improving the energy retention of the oil field and improving the development effect, too high an injection pressure may cause the opening of cracks near the fault, causing oil and gas escape and oil spills, which will not only cause oil and gas reservoir damage and reserve loss, but also cause serious environmental pollution. Therefore, determining a reasonable reservoir safety injection pressure is crucial to oil and gas field development.

[0003] For water injection development of oil fields, the conventional method usually takes 80% of the formation fracture pressure at the depth of the water injection well as the upper limit of the safe injection pressure. However, for anticline oil fields with gas caps, in order to prevent gas channeling, water injection wells are usually deployed near the gas cap area, while oil production wells are deployed at relatively low positions. At this time, we cannot only pay attention to whether the formation near the water injection well is fractured, but we should also pay attention to the formation pressure at the junction of the top of the reservoir and the cap rock not exceeding the fracture pressure.

[0004] This is because the formation pressure gradient in the gas cap area is much lower than that in the pure oil area. When the water injection well injects water near the gas-oil interface, the gas cap area can transmit pressure, causing the pressure at the water injection well to be easily transmitted to the top of the reservoir. If conventional methods are still used to determine the maximum safe injection pressure, the integrity of the top cap rock may be destroyed, causing oil and gas to escape. Therefore, conventional methods are no longer suitable for reservoir development under such circumstances.

[0005] Therefore, there is an urgent need for a method to determine the safe injection pressure for water injection development of anticline reservoirs with gas caps. Summary of the invention

[0006] In view of the problems existing in the prior art, the purpose of the present invention is to provide a calculation method and device, equipment and medium for the safe injection pressure of high-position water injection, so as to achieve efficient and accurate determination of the safe injection pressure in the water injection development of anticline oil reservoirs with gas caps.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for calculating the safe injection pressure of high-position water injection, the calculation method comprising:

[0009] Based on the test data of the drilling process, the average formation fracture pressure gradient T is obtained. f ;

[0010] Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained. gas and the depth of the gas-oil interface in the reservoir D goc ;

[0011] Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained. top ;

[0012] According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained. inj ;

[0013] Comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir D goc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the pressure at the top structure of the reservoir does not exceed 80% of the fracture pressure of the formation at the depth, the maximum safety injection pressure P of the bottom hole of the water injection well near the high part of the gas cap area is calculated. injmax .

[0014] The calculation method provided by the present invention realizes the maximum safe injection pressure P of the bottom hole of the water injection well near the high part of the gas cap area by integrating specific drilling parameters, oil field development parameters and seismic structural interpretation. injmax The accurate confirmation of the injection-production system lays the foundation for optimizing the injection-production well ratio, which is beneficial to improving the effect of oilfield development.

[0015] As a preferred technical solution of the present invention, the average formation fracture pressure gradient T f Including: based on the formation leakage test data or the fracture pressure test data in the drilling process, a curve of the relationship between the formation fracture pressure and the formation depth is drawn.

[0016] As a preferred technical solution of the present invention, the formation pressure gradient T gas Including: based on the oil field pressure sampling data and well logging interpretation data, draw a curve of reservoir pressure change with formation depth.

[0017] As a preferred technical solution of the present invention, the pressure P at the top structural depth of the reservoir top The calculation formula includes:

[0018]

[0019] Where D goc , D top and D inj The unit of P is m; top , P inj The unit of is MPa; ρ w is the density of water, kg / m 3 ; g is the acceleration due to gravity, which is 9.8N / Kg; T gas The unit is MPa / m; P inj It is the bottom hole injection pressure of the water injection well near the high part of the gas cap area, MPa.

[0020] As a preferred technical solution of the present invention, the calculation formula based on the fact that the pressure at the top structure of the reservoir does not exceed 80% of the fracture pressure of the formation at the depth as the safety injection pressure standard includes:

[0021] P top ≤0.8·T f D top .

[0022] As a preferred technical solution of the present invention, the maximum safe injection pressure P of the water injection well at the bottom of the water injection well near the high part of the gas cap area is injmax The calculation formula includes:

[0023]

[0024] Where P injmax The unit is MPa; T f The unit is MPa / m.

[0025] In a second aspect, the present invention provides a device for calculating the safe injection pressure of high-position water injection, the calculation device comprising:

[0026] The parameter acquisition module is used to obtain the average formation fracture pressure gradient T according to the test data of the drilling process. f ; Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained gas and the depth of the gas-oil interface in the reservoir D goc ; Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained top ; According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained inj ;

[0027] Calculation module for comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir Dgoc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the structural depth pressure at the top of the reservoir does not exceed 80% of the formation fracture pressure at that depth, the maximum safety injection pressure at the bottom of the well near the high part of the gas cap area is calculated.

[0028] As a preferred technical solution of the present invention, the parameter acquisition module includes: a first parameter acquisition module and a second parameter acquisition module;

[0029] The first parameter acquisition module is used to draw a curve of the relationship between formation fracture pressure and formation depth based on the formation leakage test data or fracture pressure test data during drilling to obtain the average formation fracture pressure gradient T f ;

[0030] The second parameter acquisition module is used to draw a curve of reservoir pressure variation with formation depth based on the oil field pressure sampling data and logging interpretation data to obtain the formation pressure gradient T in the gas cap area of ​​the reservoir. gas .

[0031] In a third aspect, the present invention provides an electronic device, the electronic device comprising:

[0032] at least one processor; and a memory communicatively coupled to the at least one processor;

[0033] Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for calculating the safe injection pressure of high-position water injection as described in the first aspect.

[0034] In a fourth aspect, the present invention provides a computer storage medium storing computer executable instructions, which, when executed by a processor, implements the method for calculating the safe injection pressure of high-position water injection as described in the first aspect.

[0035] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0036] The method provided by the present invention can improve the prediction accuracy of the safe injection pressure of anticline oil reservoirs with high-position water injection development where a gas cap exists, and is helpful to accurately predict the maximum water injection volume under the premise of ensuring the safe development and production of the oil field, laying a foundation for optimizing the injection-production system and the injection-production well ratio, and is beneficial to improving the development effect of the oil field. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of a method for calculating the safe injection pressure of high-position water injection provided by an embodiment of the present invention;

[0038] Figure 2 It is a schematic diagram of a device for calculating the safe injection pressure of high-position water injection provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of an electronic device provided by an embodiment of the present invention;

[0040] Figure 4 This is the oil and gas distribution map of the H27 layer of the J oil field in Example 1 of the present invention;

[0041] Figure 5 This is a diagram showing the injection-production relationship of an anticline reservoir with a high-position water injection development with a gas cap in Example 1 of the present invention;

[0042] Figure 6 It is a graph of 15 formation leakage test results during drilling at the same layer of the oil field and the adjacent oil field in Example 1 of the present invention;

[0043] Figure 7 It is the pressure test data and analysis result diagram of the H27 layer of the J oil field in Example 1 of the present invention.

[0044] In the figure: 10 - electronic device, 11 - processor, 12 - ROM, 13 - RAM, 14 - bus, 15 - I / O interface, 16 - input unit, 17 - output unit, 18 - storage unit, 19 - communication unit.

[0045] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0046] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0047] This embodiment provides a method for calculating the safe injection pressure of high-position water injection, and the flow chart is as follows: Figure 1 As shown, the calculation method includes:

[0048] Based on the test data of the drilling process, the average formation fracture pressure gradient T is obtained. f ;

[0049] Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained. gas and the depth of the gas-oil interface in the reservoir D goc ;

[0050] Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained. top ;

[0051] According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained. inj ;

[0052] Comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir D goc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the pressure at the top structure of the reservoir does not exceed 80% of the fracture pressure of the formation at the depth, the maximum safety injection pressure P of the bottom hole of the water injection well near the high part of the gas cap area is calculated. injmax .

[0053] Specifically, the average formation fracture pressure gradient T is obtained f Including: based on the formation leakage test data or the fracture pressure test data in the drilling process, a curve of the relationship between the formation fracture pressure and the formation depth is drawn.

[0054] Specifically, the formation pressure gradient T gas Including: based on the oil field pressure sampling data and well logging interpretation data, draw a curve of reservoir pressure change with formation depth.

[0055] Specifically, the depth of the gas-oil interface in the reservoir D is obtained based on the oilfield pressure sampling data or logging interpretation data. goc If the drilling encounters the gas-oil interface, the depth D of the gas-oil interface is directly determined based on the logging interpretation data. goc If the drilling does not encounter the gas-oil interface, the depth D of the gas-oil interface is determined based on the pressure measurement data and pressure regression. goc .

[0056] Specifically, the pressure P at the top structural depth of the reservoir is top The calculation formula includes:

[0057]

[0058] Where D goc , D top and D inj The unit of P is m; top , P inj The unit of is MPa; ρ w is the density of water, kg / m 3; g is the acceleration due to gravity, which is 9.8N / Kg; T gas The unit is MPa / m; P inj It is the bottom hole injection pressure of the water injection well near the high part of the gas cap area, MPa.

[0059] Specifically, the calculation formula based on the fact that the pressure at the top structure of the reservoir does not exceed 80% of the fracture pressure of the formation at the depth as the safety injection pressure standard includes:

[0060] P top ≤0.8·T f D top .

[0061] Specifically, the calculation formula for the maximum safe injection pressure at the bottom of the water injection well near the high part of the gas cap area includes:

[0062]

[0063] Where P injmax The unit is MPa; T f The unit is MPa / m.

[0064] Furthermore, this embodiment provides a device for calculating the safe injection pressure of high-position water injection, such as Figure 2 As shown, the computing device includes:

[0065] The parameter acquisition module is used to obtain the average formation fracture pressure gradient T according to the test data of the drilling process. f ; Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained gas and the depth of the gas-oil interface in the reservoir D goc ; Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained top ; According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained inj ;

[0066] Calculation module for comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir D goc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the structural depth pressure at the top of the reservoir does not exceed 80% of the formation fracture pressure at that depth, the maximum safety injection pressure at the bottom of the well near the high part of the gas cap area is calculated.

[0067] Specifically, the parameter acquisition module includes: a first parameter acquisition module and a second parameter acquisition module;

[0068] The first parameter acquisition module is used to draw a curve of the relationship between formation fracture pressure and formation depth based on the formation leakage test data or fracture pressure test data during drilling to obtain the average formation fracture pressure gradient T f ;

[0069] The second parameter acquisition module is used to draw a curve of reservoir pressure variation with formation depth based on the oil field pressure sampling data and logging interpretation data to obtain the formation pressure gradient T in the gas cap area of ​​the reservoir. gas .

[0070] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0071] Further, the present invention provides an electronic device, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0072] like Figure 3 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The I / O interface 15 is also connected to the bus 14.

[0073] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0074] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a method for calculating the safe injection pressure of high-site water injection.

[0075] In some embodiments, the calculation method of the high-site water injection safety injection pressure can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the calculation method of the high-site water injection safety injection pressure described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the calculation method of the high-site water injection safety injection pressure by any other appropriate means (for example, by means of firmware).

[0076] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0077] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0078] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0079] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0080] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0081] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0082] The server provided in this embodiment includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the above-mentioned method for calculating the safe injection pressure of water injection at a high position is implemented.

[0083] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0084] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments of the present invention may all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0085] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0086] For software implementation, the techniques described in the present invention can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in the present application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0087] Further, in order to illustrate the recognition effect that can be achieved by the method for calculating the safe injection pressure of high-position water injection provided by the present invention, an actual example is used for illustration, as follows:

[0088] Example 1

[0089] This embodiment provides a calculation process for the safe injection pressure of anticline reservoirs with high-position water injection development with gas caps, which is as follows:

[0090] Taking the J oilfield in the Albert Lake area of ​​East Africa as an example, the oilfield is a sandstone reservoir with a burial depth of 300-710m. It is a river-lake transition delta phase deposit. The reservoir properties are high porosity-ultra-high porosity, high permeability-ultra-high permeability, porosity of 25-35%, permeability of 3-40D, original reservoir pressure of 4-5MPa, and ground crude oil density of 0.92-0.95g / cm 3 , which is heavy - ordinary thick oil.

[0091] There is a gas cap in the H27 layer of the oil field ( Figure 4 ), the well pattern adopts a combination of water injection near the gas cap area and oil production in the middle ( Figure 5 ). Since the oil reservoir is shallowly buried and has well-developed reservoir faults, the risk of oil spill is very high. Accurately predicting the safe injection pressure of water injection wells is of great significance for formulating a reasonable production system. The method proposed in the present invention is used to take two water injection wells of the oil reservoir as an example to illustrate how to use the method of the present invention to determine the safe injection pressure.

[0092] Using the formation leakage test data during the drilling process of the J oilfield, the formation fracture pressure gradient at different depths can be directly obtained. The results of 15 formation leakage tests during the drilling process of the same layer in this oilfield and adjacent oilfields were statistically analyzed. Figure 6 As shown, the average formation fracture pressure gradient T of the oil field is determined f It is 0.013MPa / m.

[0093] Based on the pressure sampling data and logging interpretation data of J Oilfield, the formation pressure gradient T in the gas cap area of ​​the reservoir is determined by the slope of the regression line of the pressure measurement points in the gas cap area. gas The gas-oil interface depth D is determined by the intersection of the regression lines of the pure oil zone and the gas cap zone. goc is 436m, such as Figure 7 shown.

[0094] According to the seismic structural interpretation data of J oilfield, the top structural depth of the reservoir D is obtained. top It is 388m.

[0095] According to the well deployment of H27 reservoir development in J oilfield, it was determined that the formation depths of the two water injection wells INJ1 and INJ2 near the high part of the gas cap area were 440m and 448m respectively.

[0096] The maximum safe injection pressure of two water injection wells near the high gas cap area of ​​H27 reservoir in J oilfield was calculated according to the calculation formula, and compared with the maximum safe injection pressure P of the conventional method (80% of the formation fracture pressure at the depth of the formation where the water injection well is located). injmax A comparison was made, such as Figure 7 The results are shown in Table 1.

[0097] Table 1

[0098] hashtag <![CDATA[D inj / m]]> <![CDATA[D inj -D goc / m]]> Conventional method maximum safe injection pressure / MPa Maximum safe injection pressure of the new method / MPa INJ1 440 4 4.58 4.08 INJ2 448 12 4.66 4.16

[0099] comprehensive Figure 7 As shown in Table 1, the maximum safe injection pressure P determined by the method provided in this application is injmax In view of the fact that the gas cap conducts pressure, and the pressure gradient of the gas layer is very small and the pressure conduction is fast, in order to ensure safe production, the method proposed in the present invention starts from the essential principle, and the calculation result of the safe injection pressure of the anticline oil reservoir with high water injection development in the presence of gas cap is more accurate, which has important guiding significance for optimizing the injection and production system and preventing oil spill accidents.

[0100] It is stated that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0101] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0102] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0103] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for calculating the safe injection pressure of high-position water injection, characterized in that: The calculation method includes: Based on the test data of the drilling process, the average formation fracture pressure gradient T is obtained. f ; Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained. gas and the depth of the gas-oil interface in the reservoir D goc ; Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained. top ; According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained. inj ; Comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir D goc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the pressure at the top structure of the reservoir does not exceed 80% of the fracture pressure of the formation at the depth, the maximum safety injection pressure P of the bottom hole of the water injection well near the high part of the gas cap area is calculated. injmax .

2. The method for calculating the safe injection pressure of high-position water injection according to claim 1, characterized in that: The average formation fracture pressure gradient T f Including: based on the formation leakage test data or the fracture pressure test data in the drilling process, a curve of the relationship between the formation fracture pressure and the formation depth is drawn.

3. The method for calculating the safe injection pressure of high-position water injection according to claim 1, characterized in that: The formation pressure gradient T in the gas cap area of ​​the reservoir gas Including: based on the oil field pressure sampling data and logging interpretation data, draw the curve of reservoir pressure change with formation depth.

4. The method for calculating the safe injection pressure of high-position water injection according to claim 1, characterized in that: The pressure P at the top structural depth of the reservoir top The calculation formula includes: Where D goc , D top and D inj The unit of P is m; top , P inj The unit of is MPa; ρ w is the density of water, kg / m 3 ; g is the acceleration due to gravity, which is 9.8N / Kg; T gas The unit is MPa / m; P inj It is the bottom hole injection pressure of the water injection well near the high part of the gas cap area, MPa.

5. The method for calculating the safe injection pressure of high-position water injection according to claim 4, characterized in that: The calculation formula based on the top structural depth pressure of the reservoir not exceeding 80% of the fracture pressure of the formation at the depth as the safe injection pressure standard is include: P top ≤0.8·T f D top 。 6. The method for calculating the safe injection pressure of high-position water injection according to claim 5, characterized in that: The maximum safe injection pressure P of the water injection well at the bottom of the high part near the gas cap area injmax The calculation formula includes: Where P injmax The unit is MPa; T f The unit is MPa / m.

7. A device for calculating the safe injection pressure of high-position water injection, characterized in that: The computing device comprises: The parameter acquisition module is used to obtain the average formation fracture pressure gradient T according to the test data of the drilling process. f ; Based on the oilfield pressure sampling data and / or logging interpretation data, the formation pressure gradient T in the gas cap area of ​​the reservoir is obtained gas and the depth of the gas-oil interface in the reservoir D goc ; Based on the seismic structural interpretation data, the top structural depth of the reservoir D is obtained top ; According to the well location deployment of oil reservoir development, the formation depth D of the water injection well near the high part of the gas cap area is obtained inj ; Calculation module for comprehensive average formation fracture pressure gradient T f , gas cap zone formation pressure gradient T gas , Depth of gas-oil interface in reservoir D goc , reservoir top structural depth D top and the formation depth D of the injection well located in the high part of the gas cap area inj Calculate the pressure P at the top structural depth of the reservoir top Then, based on the safety injection pressure standard that the structural depth pressure at the top of the reservoir does not exceed 80% of the formation fracture pressure at that depth, the maximum safety injection pressure at the bottom of the well near the high part of the gas cap area is calculated.

8. The computing device according to claim 7, wherein: The parameter acquisition module includes: a first parameter acquisition module and a second parameter acquisition module; The first parameter acquisition module is used to draw a curve of the relationship between formation fracture pressure and formation depth based on the formation leakage test data or fracture pressure test data during drilling to obtain the average formation fracture pressure gradient T f ; The second parameter acquisition module is used to draw a curve of reservoir pressure variation with formation depth based on the oil field pressure sampling data and logging interpretation data to obtain the formation pressure gradient T in the gas cap area of ​​the reservoir. gas .

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for calculating the safety injection pressure of high-position water injection as described in any one of claims 1-6.

10. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by the processor, the method for calculating the safe injection pressure of high-position water injection according to any one of claims 1 to 6 is implemented.

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