CN-122020326-A - Water breakthrough time prediction method and device for oil well in deep water oil reservoir

CN122020326ACN 122020326 ACN122020326 ACN 122020326ACN-122020326-A

Abstract

The invention provides a water breakthrough time prediction method and device for an oil well in a deep water oil reservoir, and relates to the technical field of oil reservoir engineering, wherein the method comprises the steps of classifying the oil reservoirs in the deep water oil reservoir, and establishing an objective function of dynamic relative permeability of a rock core in the deep water oil reservoir, displacement speed of the rock core and water saturation aiming at each type of the oil reservoirs; and predicting the water breakthrough time of the oil well in the deep water oil reservoir according to the derivative, the static pressure of the deep water oil reservoir, the stratum pressure of the deep water oil reservoir, the porosity of the reservoir in the deep water oil reservoir, the pore volume in a seepage area between injection and production wells, the target water injection quantity of the oil well and a target formula. Therefore, on one hand, the influence of dynamic relative permeability on water breakthrough time is considered, the accuracy of water breakthrough time prediction is improved, on the other hand, the anhydrous oil extraction period of an oil well is prolonged, the accumulated oil yield and the recovery ratio of the oil well are improved, and a basis is provided for subsequent development and adjustment.

Inventors

LU WENMING
PENG ZEYANG
LI MIAO
LI LINDI

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司石油勘探开发研究院

Dates

Publication Date: 20260512
Application Date: 20241111

Claims (10)

1. A method for predicting water breakthrough time for an oil well in a deep water reservoir, the method comprising: Classifying reservoirs in a deep water oil reservoir, and establishing an objective function of dynamic relative permeability of a core in the deep water oil reservoir, displacement speed of the core and water saturation aiming at each type of reservoir; Determining a derivative of the objective function at water saturation of the water drive front; Predicting the water breakthrough time of an oil well in the deepwater oil reservoir according to the derivative, the static pressure of the deepwater oil reservoir, the stratum pressure of the deepwater oil reservoir, the porosity of the reservoir in the deepwater oil reservoir, the pore volume in a seepage area between injection and production wells, the target water injection rate of the oil well and a target formula.
2. The method of claim 1, wherein the reservoirs are categorized by: And counting physical parameters of the rock core, and classifying the reservoir based on the physical parameters, wherein the physical parameters comprise porosity and permeability.
3. The method of claim 2, wherein the objective function is determined by: calculating the average value of the physical property parameters corresponding to each type of reservoir, and manufacturing a corresponding artificial core; performing a core displacement experiment on each artificial core to obtain the dynamic relative permeability of the artificial core corresponding to different displacement speeds and different water saturation; the objective function of the dynamic relative permeability with the displacement velocity and the water saturation is established.
4. The method of any one of claims 1-3, wherein the dynamic relative permeability comprises an oil phase dynamic relative permeability and a water phase dynamic relative permeability; The first objective function is obtained by: Inputting the dynamic relative permeability of the oil phase, the displacement speed and the water saturation into an SVM model for each type of the reservoir to obtain the first objective function; The second objective function is obtained by: The dynamic relative permeability of the aqueous phase, the displacement velocity, the water saturation are input into the SVM model for each type of reservoir, resulting in the second objective function.
5. The method of claim 4, wherein the first objective function is: Wherein K ro denotes the dynamic relative permeability of the oil phase, V denotes the displacement speed, S w denotes the water saturation, and A 1 、B 1 、C 1 、D 1 、E 1 、F 1 denotes the correlation coefficient; The second objective function is: Wherein K rw refers to the dynamic relative permeability of the aqueous phase, and A 2 、B 2 、C 2 、D 2 、E 2 、F 2 refers to the correlation coefficient.
6. The method of any one of claims 1-5, wherein the pore volume is determined by: determining an oil-containing area diagram and a Lian Jing section diagram of the oil well, and a sand body structure diagram and an oil-water interface of the deep water oil reservoir; and determining the seepage area according to the oil-containing area diagram, the well connecting section diagram, the sand body structure diagram and the oil-water interface so as to determine the pore volume.
7. The method of any one of claims 1-6, wherein the target water injection amount is determined by: and determining the target water injection rate according to the corresponding relation between the water injection well and the production well in the reservoir and the water injection rate of the water injection well.
8. The method of any one of claims 1-7, wherein the target formula is: Wherein T refers to water breakthrough time of an oil well, phi 0 refers to porosity of a reservoir in a deep water reservoir; The method is characterized by comprising the following steps of (1) setting a static pressure of a deep water reservoir, wherein p i is the stratum pressure of the deep water reservoir, and A (x) is the seepage area between injection and production wells; Referring to the pore volume of the seepage region, Q iw refers to the target water injection rate of the well, and f w ' f (S wf ) refers to the derivative of the water saturation of the water cut at the front of the water drive.
9. A storage medium comprising a series of instructions for performing the method steps of any one of claims 1-8.
10. A water breakthrough time prediction device for an oil well in a deep water reservoir, characterized in that a method according to any of claims 1-8 is performed, the device comprising: the establishing module is used for classifying reservoirs in the deepwater oil reservoirs and establishing an objective function of dynamic relative permeability of a rock core in the deepwater oil reservoirs, displacement speed of the rock core and water saturation aiming at each type of reservoir; A determination module for determining a derivative of the objective function at water saturation of a water drive front; The prediction module is used for predicting the water breakthrough time of the oil well in the deepwater oil reservoir according to the derivative, the static pressure of the deepwater oil reservoir, the stratum pressure of the deepwater oil reservoir, the porosity of the reservoir in the deepwater oil reservoir, the pore volume in a seepage region between injection and production wells, the target water injection rate of the oil well and a target formula.

Description

Water breakthrough time prediction method and device for oil well in deep water oil reservoir Technical Field The invention relates to the technical field of oil reservoir engineering, in particular to a water breakthrough time prediction method and device for an oil well in a deep water oil reservoir. Background Deepwater reservoirs are the forefront in the world oil and gas reserves and yields and are highly focused research objects at home and abroad. Large-area deep water oil reservoirs are distributed in China, and huge innovation space exists in the aspect of geological research of the deep water oil reservoirs. And the water breakthrough time of the oil well in the deep water oil reservoir is predicted, so that the anhydrous oil production period of the oil well can be prolonged, and the accumulated oil production and the final recovery rate of the oil well can be improved. Therefore, the prediction of the water breakthrough time of an oil well in a deep water oil reservoir is particularly important. In the deep water oil reservoir development process, relative permeability changes along with the change of seepage velocity, so that the water breakthrough time of an oil well is influenced. In the prior art, the water breakthrough time prediction method mainly comprises an oil reservoir engineering method and a numerical simulation method, however, neither the former nor the latter takes dynamic relative permeability into consideration, so that the water breakthrough time prediction is inaccurate. Aiming at the problems in the prior art, the invention provides a water breakthrough time prediction method and device for an oil well in a deep water oil reservoir. Disclosure of Invention Aiming at the problems of the prior art, the invention provides a water breakthrough time prediction method and a device for an oil well in a deep water oil reservoir, wherein the method comprises the following steps: Classifying reservoirs in a deep water oil reservoir, and establishing an objective function of dynamic relative permeability of a core in the deep water oil reservoir, displacement speed of the core and water saturation aiming at each type of reservoir; Determining a derivative of the objective function at water saturation of the water drive front; Predicting the water breakthrough time of an oil well in the deepwater oil reservoir according to the derivative, the static pressure of the deepwater oil reservoir, the stratum pressure of the deepwater oil reservoir, the porosity of the reservoir in the deepwater oil reservoir, the pore volume in a seepage area between injection and production wells, the target water injection rate of the oil well and a target formula. According to one embodiment of the invention, the reservoirs are classified by: And counting physical parameters of the rock core, and classifying the reservoir based on the physical parameters, wherein the physical parameters comprise porosity and permeability. According to one embodiment of the invention, the objective function is determined by: calculating the average value of the physical property parameters corresponding to each type of reservoir, and manufacturing a corresponding artificial core; performing a core displacement experiment on each artificial core to obtain the dynamic relative permeability of the artificial core corresponding to different displacement speeds and different water saturation; the objective function of the dynamic relative permeability with the displacement velocity and the water saturation is established. According to one embodiment of the invention, the dynamic relative permeability comprises an oil phase dynamic relative permeability and a water phase dynamic relative permeability; The first objective function is obtained by: Inputting the dynamic relative permeability of the oil phase, the displacement speed and the water saturation into an SVM model for each type of the reservoir to obtain the first objective function; The second objective function is obtained by: The dynamic relative permeability of the aqueous phase, the displacement velocity, the water saturation are input into the SVM model for each type of reservoir, resulting in the second objective function. According to one embodiment of the invention, the first objective function is: Wherein K ro denotes the dynamic relative permeability of the oil phase, V denotes the displacement speed, S w denotes the water saturation, and A 1、B1、C1、D1、E1、F1 denotes the correlation coefficient; The second objective function is: Wherein K rw refers to the dynamic relative permeability of the aqueous phase, and A 2、B2、C2、D2、E2、F2 refers to the correlation coefficient. According to one embodiment of the invention, the pore volume is determined by: determining an oil-containing area diagram and a Lian Jing section diagram of the oil well, and a sand body structure diagram and an oil-water interface of the deep water oil reservoir; and determining the seepage area acco