Method for integral profile control and plugging of water encroachment and steam channeling of heavy oil reservoir with edge and bottom water

Patent metadata

Field	Value
Publication number	US-11719081-B2
Application number	US-202017596156-A
Country	US
Kind code	B2
Filing date	Apr 30, 2020
Priority date	Jun 10, 2019
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

Disclosed is a method for performing integral plugging control on water invasion and steam channeling of an edge-bottom water heavy oil reservoir. The method for performing integral plugging control on water invasion and steam channeling of an edge-bottom water heavy oil reservoir comprises the following steps: (1) selecting an oil reservoir; (2) arranging a huff-puff well; (3) performing steam huff-puff development; and (4) performing integral plugging control. An integral plugging control technology is used for the method, a high-strength nitrogen foam system is injected by means of well rows at different positions in the oil reservoir, and effective plugging walls are formed at different positions from the edge-bottom water to reduce water invasion and steam channeling.

First claim

What is claimed is:

1. A method for integral profile control and plugging of water encroachment and steam channeling of a heavy oil reservoir with edge and bottom water, comprising the following steps:
(i) selecting an oil reservoir: roughly screening an appropriate oil reservoir according to the following conditions: the oil reservoir is a heavy oil reservoir with edge and bottom water, the viscosity of stock tank oil at 50° C. is less than 100000 mPa·s, a buried depth of the oil reservoir is less than 1000 m, an effective thickness is greater than 5 m, an initial oil bearing saturation is greater than 0.5, a penetration rate is greater than 200 mD, and a volume ratio of a water body to an oil layer is less than 500;
(ii) arranging huff-puff wells: drilling the huff-puff wells in the oil layer according to a row-well pattern, wherein the huff-puff wells are vertical or horizontal wells; determining the number of well rows according to an area of the oil reservoir, wherein at least 3 columns of huff-puff well rows are arranged in the oil layer, a distance between two adjacent columns of well rows is 100-150 m, and a distance between two adjacent huff-puff wells in each column of well rows is 100-150 m; one column of well rows close to water body is a first line of well rows, followed by a second line of well rows and a third line of well rows, and so on, and a distance between the first line of well rows and the water body is greater than 150 m;
(iii) developing through cyclic steam stimulation: firstly beginning a first cycle of cyclic steam stimulation, wherein a steam injection volume for the first line of well rows is 1000-1200 t, a steam injection volume for the second line of well rows is 1500-1800 t, and a steam injection volume for the third line of well rows is 2000-2200 t; after the steam injection, soaking the wells for 3-5 days, and after the soaking, opening the wells for production, wherein a ratio of a fluid output of the first line of well rows to a cold water equivalent volume of the injected steam is less than 5; a ratio of a fluid output of the second line of well rows to a cold water equivalent volume of the injected steam is less than 10; a ratio of a fluid output of the third line of well rows to a cold water equivalent volume of the injected steam is less than 20; and huff-puff parameters of a next cycle are consistent with those of the first cycle;
(iv) carrying out the integral profile control and plugging: with the increase of huff-puff cycles, the formation pressure drops gradually, water encroachment and steam channeling occur, an integral profile control and plugging technology is adopted, and specific operations are as follows:
(a) after a moisture content of the first line of well rows is greater than 90%, injecting a high-intensity nitrogen foam system at the same time of a steam injection phase of the first line of well rows, reducing a cyclic steam injection volume of the first line of well rows to 800-1000 t, injecting nitrogen with the steam in a whole process, wherein an injection volume is calculated according to a gas-to-liquid ratio of foam formed downhole of 2:1; and after soaking the wells for 3-5 days, carrying out oil recovery;
(b) injecting a nitrogen foam system at the same time of steam injection of the second line of well rows, wherein a concentration of a foaming agent is 0.5%; a steam injection volume of the second line of well rows is 1500-1800 t; injecting the nitrogen with the steam in the whole process, wherein a nitrogen injection volume is calculated according to a gas-to-liquid ratio of the foam formed downhole of 3:1; and after the steam injection is finished, increasing well soaking time to 5-6 days, and then opening the wells for production; and
(c) injecting the nitrogen foam system at the same time of the steam injection of the third line of well rows, wherein the concentration of the foaming agent is 0.5%; a steam injection volume of the third line of well rows is 1500-2500 t; injecting the nitrogen with the steam in the whole process, wherein the nitrogen injection volume is calculated according to a gas-to-liquid ratio of the foam formed downhole of 4:1; and after the steam injection is finished, increasing the well soaking time to 6-8 days, and then opening the wells for production.

2. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 1 , characterized in that the high-intensity nitrogen foam system in the step (4) adopts a solid particle reinforced foam system or a high-temperature resistant gel foam system.

3. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 2 , characterized in that a concentration of solid particles in the solid particle reinforced foam system is 0.5%-1%, and the concentration of the foaming agent is 0.5%.

4. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 3 , characterized in that the solid particles in the solid particle reinforced foam system adopt coal ash, clay particles or nano particles.

5. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 2 , characterized in that the high-temperature resistant gel foam system comprises a high-temperature resistant gel plugging agent injected into a stratum and nitrogen foam injected at the same time of cyclic steam stimulation.

6. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 5 , characterized in that the high-temperature resistant plugging agent adopts tanning extracts or temperature-sensitive gel.

7. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 5 , characterized in that an injection amount of the high-temperature resistant gel plugging agent is 30-50 t.

8. The method for integral profile control and plugging of water encroachment and steam channeling of the heavy oil reservoir with edge and bottom water according to claim 5 , characterized in that the concentration of the foaming agent in the high-temperature resistant gel foam system is 0.5%.

Assignees

• Univ China Petroleum

Inventors

• Lu Teng
• Li Zhaomin
• Li Binfei
• Li Songyan

Classifications

• E21B43/24 Primary

  using heat, e.g. steam injection · CPC title

• E21B43/166 Primary

  Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium (CO2 injection E21B43/164; steam injection E21B43/24) · CPC title