Cement compositions containing phyllosilicate and methods of use

Patent metadata

Field	Value
Publication number	US-11780775-B2
Application number	US-201916516625-A
Country	US
Kind code	B2
Filing date	Jul 19, 2019
Priority date	Jul 19, 2019
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

Cement compositions containing a hydraulic cement, a synthetic phyllosilicate (e.g. Laponite®), and silica flour. The cement compositions may optionally include other additives such as an expandable agent, a defoamer, and a fluid loss controller. Cement slurries and wellbore cements made therefrom are also specified. The inclusion of the synthetic phyllosilicate has enhanced the mechanical strength, improved the density homogeneity, as well as decreased the permeability of the wellbore cement, making it suitable for cementing oil and gas wells under high pressure and high temperature (HPHT) conditions.

First claim

The invention claimed is:

1. A cement composition, comprising:
a hydraulic cement;
silica flour;
a defoamer:
an expandable agent;
a fluid loss controller; and
from 0.1 to 0.5 wt % (BWOC) of a synthetic phyllosilicate comprising SiO 2 , MgO, and Li 2 O,
wherein:
a weight ratio of the hydraulic cement to the synthetic phyllosilicate is from 200:1 to 1,000:1,
a combined weight of SiO 2 and MgO is 80-95 wt % of a total weight of the synthetic phyllosilicate; and
the synthetic phyllosilicate has a weight ratio of SiO 2 to MgO in a range of 3:2 to 7:2.

2. The cement composition of claim 1 , wherein the synthetic phyllosilicate further comprises Na 2 O.

3. The cement composition of claim 1 , wherein the synthetic phyllosilicate is in the form of spherical particles with an average particle size of 10-100 nm, and a BET surface area of 300-1,000 m 2 /g.

4. The cement composition of claim 1 , wherein the synthetic phyllosilicate has a bulk density of 800-1,200 kg/m 3 .

5. The cement composition of claim 1 , wherein the synthetic phyllosilicate comprises a hectorite clay.

6. The cement composition of claim 1 , wherein a weight ratio of the hydraulic cement to the silica flour is in a range of 2:1 to 5:1.

7. The cement composition of claim 1 , wherein the hydraulic cement is selected from the group consisting of an API Class A Portland cement, an API Class G Portland cement, an API Class H Portland cement, and a Saudi Class G hydraulic cement.

8. A wet cement slurry, comprising:
the cement composition of claim 1 ; and
water in an amount of 40-50% by weight of the hydraulic cement.

9. The wet cement slurry of claim 8 , which has a plastic viscosity in a range of 320-380 cP.

10. The wet cement slurry of claim 8 , which has a yield point of 50-70 lb f /100 ft 2 .

11. The wet cement slurry of claim 8 , which has a ten-second gel strength of 9.8-14 lb f /100 ft 2 , and a ten-minute gel strength of 26-32 lb f /100 ft 2 .

12. A method of cementing a portion of a wellbore, the method comprising:
introducing the wet cement slurry of claim 8 , into the portion of the wellbore; and
allowing the wet cement slurry to cure thereby forming a wellbore cement.

13. The method of claim 12 , wherein the wellbore has a temperature in a range of 70-300° C., and a pressure of 1-40 MPa.

14. The method of claim 12 , wherein the wellbore is at least one selected from the group consisting of a horizontal wellbore, a vertical wellbore, and a multi-lateral wellbore.

15. The method of claim 13 , wherein the wellbore cement has a compressive strength of 40-55 MPa.

16. The method of claim 13 , wherein the wellbore cement has a gas permeability of 0.03-0.045 millidarcy (mD).

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Elkatatny Salaheldin
• Mahmoud Ahmed Abdulhamid
• Ahmed Abdulmalek

Classifications

• C04B28/26 Primary

  Silicates of the alkali metals · CPC title

• C04B7/02

  Portland cement · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B28/184

  based on an oxide other than lime · CPC title

• C09K8/487

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