Well cementing method for improving well cementing quality by controlling hydration heat of cement slurry

Patent metadata

Field	Value
Publication number	US-11926787-B2
Application number	US-202016854376-A
Country	US
Kind code	B2
Filing date	Apr 21, 2020
Priority date	Jun 24, 2019
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A well cementing method is described for improving cementing quality by controlling the hydration heat of cement slurry. By controlling the degree and/or rate of hydration heat release from cement slurry, the method improves the hydration heat release during formation of cement with curing of cement slurry, improves the binding quality between the cement and the interfaces, and in turn improves the cementing quality at the open hole section and/or the overlap section. The cementing method improves cementing quality of oil and gas wells and reduces the risk of annular pressure.

First claim

The invention claimed is:

1. A well cementing method for improving cementing quality of a well, comprising: controlling the hydration heat of cement slurry to control the degree and rate of hydration heat release from the cement slurry, wherein
the method improves the hydration heat release during formation of cement with curing of cement slurry, improves the binding quality between the cement and the interfaces, and in turn improves the cementing quality at an overlap section of a well;
wherein when the controlling is achieved the cementing quality at the overlap section is improved;
wherein lowering the degree of hydration heat release from cement slurry is achieved by reducing the addition amount of a material generating a high hydration heat;
wherein lowering the rate of hydration heat release from cement slurry is achieved by adding a retarder;
wherein the well cementing is performed on a short-overlap-section well having a length of the overlap section not greater than 150 m; wherein
for well cementing with a separable setting cement slurry comprising a lead slurry and a tail slurry, wherein for the lead slurry, controlling of hydration heat is achieved by lowering the degree and rate of hydration heat release from the slurry, wherein the lead slurry is cement slurry with high strength and low elastic modulus, and its additional safety time for thickening is 60-300 minutes; and wherein for the tail slurry, controlling of hydration heat is achieved by increasing the degree and rate of hydration heat release from the slurry, wherein the tail slurry is cement slurry with high strength, and its additional safety time for thickening is 30-60 minutes;
wherein the high strength occurs when the 7-day strength is greater than 28 MPa, and the low elastic modulus occurs when the elastic modulus is less than 10 GPa.

2. The well cementing method according to claim 1 , wherein increasing the degree of hydration heat release from cement slurry is achieved by adding a material generating a high hydration heat to cement slurry.

3. The well cementing method according the claim 2 , wherein the material generating a high hydration heat includes an accelerating early strength agent.

4. The well cementing method according to claim 3 , wherein the accelerating early strength agent includes one of, or a combination of two or more of: sodium chloride, sodium carbonate, sodium formate, sodium nitrite, calcium chloride, calcium formate, calcium sulfate, calcium metasilicate, sodium aluminate, metakaolin, magnesium trisilicate, magnesium oxide, strontium sulfate, strontium carbonate, strontium nitrate, lithium carbonate, gypsum, hemihydrate gypsum, dihydrate gypsum, magnesium oxide, calcium oxide, activated slag, and ultra-fine cement.

5. The well cementing method according to claim 1 , wherein increasing the rate of hydration heat release from cement slurry is achieved by shortening the additional safety time for thickening of cement slurry.

6. The well cementing method according to claim 1 , wherein the retarder includes an AMPS-based retarder.

7. The well cementing method according claim 1 , wherein the cement component in the cement slurry is one of or a combination of two or more of: class A oil well cement, class B oil well cement, class C oil well cement, class D oil well cement, class E oil well cement, class F oil well cement, class G oil well cement, class H oil well cement, and class J oil well cement.

8. The well cementing method according to claim 7 , wherein the cement slurry further contains one of or a combination of two or more of: a toughening agent, a fluid loss additive, a dispersant, a defoaming agent, a fleeing-proof agent, silica, and water.

9. The well cementing method according to claim 1 , wherein
for well cementing with single setting cement slurry, controlling of hydration heat is achieved by lowering the degree and rate of hydration heat release from the cement slurry; wherein the cement slurry is cement slurry with high strength and low elastic modulus, and its additional safety time for thickening is 60-300 minutes;
for well cementing with multi-setting cement slurry comprising a lead slurry, an intermediate slurry and a tail slurry, wherein for the lead slurry, controlling of hydration heat is achieved by lowering the degree and rate of hydration heat release from the slurry, wherein the lead slurry is cement slurry with high strength and low elastic modulus, and its additional safety time for thickening is 60-300 minutes; wherein for the intermediate slurry, controlling of hydration heat is achieved by increasing the degree and rate of hydration heat release from the slurry, wherein the intermediate slurry is cement slurry with high strength, and its additional safety time for thickening is 60-200 minutes; and wherein for the tail slurry, controlling of hydration heat is achieved by increasing the degree and rate of hydration heat release from the slurry, wherein the tail slurry is cement slurry with high strength, and its additional safety time for thickening is 30-60 minutes.

10. A well cementing method for improving cementing quality of a well, comprising:
controlling the hydration heat of cement slurry to control the degree and rate of hydration heat release from the cement slurry, wherein
the method improves the hydration heat release during formation of cement with curing of cement slurry, improves the binding quality between the cement and the interfaces, and in turn improves the cementing quality at an overlap section of a well;
wherein for well cementing of a well of a pure overlap section, hydration heat is controlled by lowering the degree and rate of hydration heat release from cement slurry; wherein the cement slurry is cement slurry with high strength and low elastic modulus, the additional safety time is 60-300 minutes for thickening of the lead slurry and 30-200 minutes for thickening of the tail slurry;
wherein the high strength occurs when the 7-day strength is greater than 28 MPa, and the low elastic modulus occurs when the elastic modulus is less than 10 GPa.

11. A well cementing method for improving cementing quality of a well, comprising:
controlling the hydration heat of cement slurry to control the degree and rate of hydration heat release from the cement slurry;
wherein the method improves the hydration heat release during formation of cement with curing of cement slurry, improves the binding quality between the cement and the interfaces, and in turn improves the cementing quality at an overlap section of a well;
wherein when the controlling is achieved, the cementing quality at the overlap section is improved by lowering the degree and rate of hydration heat release from cement slurry;
wherein lowering the degree of hydration heat release from cement slurry is achieved by reducing the addition amount of a material generating a high hydration heat; wherein lowering the rate of hydration heat release from cement slurry is achieved by adding a retarder;
wherein the well cementing is performed on a long-overlap-section well having a length of overlap section greater than 150 m; wherein
for well cementing with single setting cement slurry, controlling of hydration heat is achieved by lowering the degree and/or rate of hydration heat release from the cement slurry; wherein the cement slurry is cement slurry with high strength and low elastic modulus, and its additional safety time for thickening is 60-300 minutes;
for well cementing with separable setting cement slurry comprising a lead slurry and a tail slurry, wherein for the lead slurry, controlling of hydration heat is achieved by lowering the degree and/or rate of hydration heat release from the slurry,

Assignees

• Petrochina Co Ltd
• Cnpc Eng Tech Res & Dev Co Ltd

Inventors

• Liu Shuoqiong
• Zhang Hua
• Jin Jianzhou
• Xu Ming
• Yu Yongjin
• Qi Fengzhong
• Qu Congfeng
• Yue Hong
• Zheng Youcheng
• Li Wei
• Ma Yong
• Zheng Youzhi
• Huang Zhao
• Yuan Jinping
• Ding Zhiwei
• Zhou Chongfeng
• Zhang Chi
• Liu Zishuai
• Ji Hongfei
• Guo Yuchao
• Xia Xiujian
• Li Yong
• Shen Jiyun
• Liu Huiting
• Feng Yusi
• Lyu Bin

Classifications

• C09K8/467 Primary

  containing additives for specific purposes · CPC title

• E21B33/14

  for cementing casings into boreholes · CPC title

• E21B33/13 Primary

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title

• C09K8/487

  Fluid loss control additives; Additives for reducing or preventing circulation loss · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title