CN-122021462-A - Method, system, equipment and medium for adjusting gas-dispelling, gas-channeling, injection and production parameters

CN122021462ACN 122021462 ACN122021462 ACN 122021462ACN-122021462-A

Abstract

The invention provides a method, a system, equipment and a medium for adjusting gas-drive gas channeling injection production parameters, which belong to the technical field of oil-gas field development engineering, and the method comprises the steps of collecting static data, dynamic data and PVT experimental data of a target oil reservoir involved in the offshore oil field gas-drive process and constructing a basic database; further establishing a gas-drive simulation mathematical model, performing automatic history fitting on the gas-drive simulation mathematical model according to block actual production data, calculating the pressure and saturation of each injection and production well and the fluid flow in an inter-well communication unit based on the history fitted model, further calculating the split coefficient between the injection and production well pairs and the gas injection utilization rate between each injection and production well pair, and identifying a gas channeling channel by comparing the single-well gas injection utilization rate with the block average gas injection utilization rate, thereby adjusting the gas injection amount of the gas injection well and the liquid yield of the production well. The method solves the problems of low gas injection efficiency and reduced crude oil recovery ratio caused by gas channeling in the offshore oilfield gas flooding development process.

Inventors

FANG YUJIA
HEI YUNHAO
YANG ERLONG
WANG MEI
DONG CHI

Assignees

东北石油大学三亚海洋油气研究院

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. A method for adjusting gas-expelling, gas-channeling, injection and production parameters, the method comprising: collecting static data, dynamic data and PVT experimental data of a target oil reservoir involved in the offshore oilfield gas flooding process to construct a basic database; taking the actual production data of the block as a fitting target, and adopting a projection gradient automatic history fitting method to perform automatic history fitting on the gas-driven simulation mathematical model so as to obtain a model after history fitting, wherein the model can reflect the actual dynamics of an oil reservoir; The method comprises the steps of performing simulation by using a model after history fitting, calculating to obtain the pressure and saturation of each injection well of a target oil reservoir and the fluid flow between wells in an inter-well communication unit, determining the split coefficient between injection well pairs based on the pressure and saturation of each injection well and the fluid flow in the inter-well communication unit, calculating the gas injection utilization rate between each injection well pair based on the split coefficient, performing statistical analysis on the gas injection utilization rate of each injection well pair to obtain the single-well gas injection utilization rate of each gas injection well and the block average gas injection utilization rate of the whole block, and identifying the gas channeling channel of the target oil reservoir by comparing the single-well gas injection utilization rate with the block average gas injection utilization rate; adjusting the gas injection amount of the gas injection well according to the deviation between the identified gas channeling channel and the single well gas injection utilization rate and the block average gas injection utilization rate of the whole block, and adjusting the liquid yield of the production well according to the gas injection amount adjustment amount and the splitting coefficient of the gas injection well.
2. The method of claim 1, wherein the simulating using the history-fitted model calculates the pressure, saturation, and inter-well fluid flow in the inter-well communication unit for each injection well of the target reservoir, comprising the steps of: Establishing an air-driven substance balance equation according to the air-driven simulation mathematical model; Performing differential discretization on the gas-driven substance balance equation to form a pressure differential equation set, and solving the pressure differential equation set to obtain pressure values of each injection well at different moments; Based on the pressure value, solving the mole fraction of each component through phase balance calculation to obtain the water saturation, the oil saturation and the gas saturation in each well control range; And obtaining the fluid flow direction and flow rate in each inter-well communication unit according to the pressure value, the water saturation, the oil saturation and the gas saturation.
3. The method of claim 1, wherein the split coefficients between pairs of injection and production wells comprise a longitudinal split coefficient and a planar split coefficient, wherein: The longitudinal split coefficient is determined by the inter-well production index, expressed as: ; Wherein, the The splitting coefficient of the i well in the k layer is the n-th time step; for the total production index of the i-well at k-layer, Is the total production index of the i-well, The production index of the k layers between the i and j wells is that N w is the number of wells, N is the time step, i and j are underground marks, and N l is the number of layers; The planar split coefficient is determined by the product of the conductivity between wells and the pressure differential, expressed as: ; Wherein, the Splitting coefficients of the k layers in the direction from the i well to the j well in the nth time step; The splitting liquid amount in the k layers of communication units from the i well to the j well is, For the total fluid volume of the i-well in the k-layer, For the average conductivity between the n-th time step i and j wells at the k layer, And The pressures of the j well and the i well at the nth time step are respectively, and N is the number of wells.
4. The method of claim 3, wherein the gas injection utilization of the injection well pair is expressed as: ; the gas injection single well utilization rate is expressed as: ; the block average gas injection utilization is expressed as: ; Wherein, the The gas injection utilization rate of the k layers in the direction from the i well to the j well in the nth time step, To split the oil in the k layers from injection well i to production well j, For k split of the layer flowing from injection well i to production well j, For the cleavage coefficient in k layers in the direction of i-well to j-well, For the flow rate of the i-well at the k-layer, For the fluidity of the i and j wells in the k-layer communication unit, o, w and g respectively represent oil, water and gas, PID is a control coefficient, N is a time step, N I represents the total number of gas injection wells, and N J represents the number of production wells; The single well gas injection utilization E i is the weighted average of the gas injection utilization of the injection well and all the communicated production wells, and the block average gas injection utilization E ave is the average of the single well gas injection utilization of all the gas injection wells.
5. The method of claim 4, wherein adjusting the gas injection rate of the gas injection well based on the deviation of the identified gas channeling and the single well gas injection utilization thereof from the block average gas injection utilization of the entire block comprises the steps of: If the single well gas injection utilization rate E i of the gas injection well is larger than the block average gas injection utilization rate E ave , increasing the gas injection quantity of the well; If the single well gas injection utilization rate E i of the gas injection well is smaller than the block average gas injection utilization rate E ave , reducing the gas injection amount of the well; The calculation formula of the optimized gas injection quantity q inew is as follows: ; Wherein, the For the change calculated based on the ratio of E i to E ave , q iold is the pre-optimized gas injection amount for gas injection well i.
6. The method of claim 1, further comprising, after said adjusting the gas injection well, performing a normalization adjustment when the optimized gas injection well total gas injection does not coincide with the historical time total gas injection, the gas injection normalized adjustment expressed as: ; The gas injection amount of the kth layer of the gas injection well at the ith opening of the n+1 time step after adjustment, Is the k layer gas injection amount of the ith gas injection well before n+1 time steps are adjusted, Is the total air injection amount of the historical time block, The total air injection of the block before the adjustment of the n+1 time steps.
7. The method according to claim 1, wherein the adjusting the production well liquid yield according to the gas injection amount adjustment amount of the gas injection well and the split coefficient, specifically adjusting the production well liquid yield by a production allocation formula, wherein the production allocation formula is expressed as: ; Wherein, the For the production of well b adjusted fluid production, For the original liquid production amount before the adjustment of the production well b, I is the number of gas injection wells communicated with the production well b, deltaQ a is the gas injection amount change amount of the gas injection well a, lambda a,b is the split coefficient between the gas injection well a and the production well b, And calculating the total change amount of the production well liquid production amount after weighting.
8. A gas-drive gas channeling injection production parameter adjustment system, comprising: The construction module is used for collecting static data, dynamic data and PVT experimental data of a target oil reservoir involved in the offshore oilfield gas flooding process so as to construct a basic database; the calibration module is used for taking the actual production data of the block as a fitting target, and adopting a projection gradient automatic history fitting method to perform automatic history fitting on the gas drive simulation mathematical model so as to obtain a model after history fitting, which can reflect the actual dynamics of the oil reservoir; The system comprises a history fitting module, an identification module, a gas injection and production well pair, a gas channeling channel and a gas channel control module, wherein the history fitting module is used for performing simulation by using the history fitting module to calculate the pressure, the saturation and the fluid flow between the injection and production wells of a target oil reservoir; The adjusting module is used for adjusting the gas injection quantity of the gas injection well according to the deviation of the identified gas channeling channel and the single well gas injection utilization rate thereof and the block average gas injection utilization rate of the whole block, and adjusting the liquid production quantity of the production well according to the gas injection quantity adjusting quantity of the gas injection well and the splitting coefficient.
9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method of any of the preceding claims 1 to 7 when the program is executed.
10. A computer readable storage medium, characterized in that the storage medium stores a computer program which, when executed by a processor, implements the method of any of the preceding claims 1-7.

Description

Method, system, equipment and medium for adjusting gas-dispelling, gas-channeling, injection and production parameters Technical Field The invention belongs to the technical field of oil and gas field development engineering, and particularly relates to a method, a system, equipment and a medium for adjusting gas-drive gas channeling injection production parameters. Background The gas channeling problem directly affects the development benefit and the resource utilization rate of the offshore low-permeability oil reservoir, the development cost of the offshore oil field is continuously increased, the efficient gas channeling identification technology and the application can directly reduce the economic loss, avoid the safety risk, and provide key guarantee for the long-term sustainable development of the offshore oil field. How to judge the development condition of the dominant channel and discover the risk of gas channeling as early as possible is a key problem to be studied at present. CO 2 is used for displacing oil, so that CO 2 can be buried underground, sealing of greenhouse gases is realized, and the recovery ratio of crude oil can be effectively improved. In offshore oil field development, the reservoir pressure can gradually decrease along with the exploitation, and the injected gas can rapidly supplement the stratum pressure to push crude oil to move to a production well. CO 2 is driven in offshore oil fields to obtain a better oil increasing effect, but the yield is obviously reduced due to gas channeling at present, the pressure distribution in an oil reservoir is uneven due to the gas channeling, partial crude oil is produced prematurely in a region, crude oil in a dead oil region can not be produced at all due to lack of effective displacement, and the economic development period of the whole oil field is directly shortened. Therefore, the analysis of the gas-flooding gas channeling needs to be carried out and corresponding adjustment measures are provided to improve the gas-flooding effect. At present, the quantitative achievement of a gas channeling channel is relatively small, injection and production parameters need to be adjusted in real time after gas channeling, the existing tracer monitoring needs to be periodically sampled and analyzed, the gas migration track cannot be tracked in real time, and the existing gas channeling model is trained on specific oilfield data, so that the cross-regional applicability of the existing gas channeling model is weak, and the problems of low gas injection efficiency and reduced crude oil recovery rate caused by the gas channeling channel in the offshore oilfield gas flooding development process are caused. Disclosure of Invention The invention provides a method, a system, equipment and a medium for adjusting gas-flooding injection and production parameters, which are used for solving the problems of low gas injection efficiency and reduced crude oil recovery ratio caused by a gas-channeling channel in the gas-flooding development process of an offshore oil field. In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect of the embodiment of the present invention, a method for adjusting a gas-dispelling, gas-channeling, injection and production parameter is provided, including the following steps: collecting static data, dynamic data and PVT experimental data of a target oil reservoir involved in the offshore oilfield gas flooding process to construct a basic database; taking the actual production data of the block as a fitting target, and adopting a projection gradient automatic history fitting method to perform automatic history fitting on the gas-driven simulation mathematical model so as to obtain a model after history fitting, wherein the model can reflect the actual dynamics of an oil reservoir; The method comprises the steps of performing simulation by using a model after history fitting, calculating to obtain the pressure, saturation and fluid flow between wells of a target oil reservoir, determining split coefficients between pairs of injection wells based on the pressure, saturation and fluid flow between wells, calculating the gas injection utilization rate between pairs of injection wells based on the split coefficients, performing statistical analysis on the gas injection utilization rate of pairs of injection wells to obtain the single-well gas injection utilization rate of each gas injection well and the block average gas injection utilization rate of the whole block, and identifying a gas channeling channel of the target oil reservoir by comparing the single-well gas injection utilization rate with the block average gas injection utilization rate; adjusting the gas injection amount of the gas injection well according to the deviation between the identified gas channeling channel and the single well gas injection utilization rate and the block average gas injection utilizati