Cement Composition And Its Relation With Compressive Strength

Patent metadata

Field	Value
Publication number	US-2021172280-A1
Application number	US-201916632462-A
Country	US
Kind code	A1
Filing date	Apr 5, 2019
Priority date	Apr 5, 2019
Publication date	Jun 10, 2021
Grant date	—

Abstract

A method for designing a cement composition may include: providing a target compressive strength and a target composition density; selecting at least one cementitious material from a plurality of cementitious materials; calculating a required amount of water to produce a cement composition with the target composition density, the cement composition comprising the water and the at least one cementitious material; calculating a compressive strength of the cement composition based at least in part on a model of compressive strength; comparing the calculated compressive strength to the target compressive strength; and preparing the cement composition with the calculated compressive strength.

First claim

What is claimed is:

1 . A method for designing a cement composition comprising:
providing a target compressive strength and a target composition density; selecting at least one cementitious material from a plurality of cementitious materials; calculating a required amount of water to produce a cement composition with the target composition density, the cement composition comprising the water and the at least one cementitious material; calculating a compressive strength of the cement composition based at least in part on a model of compressive strength; comparing the calculated compressive strength to the target compressive strength; and preparing the cement composition with the calculated compressive strength.

2 . The method of claim 1 further comprising:
adjusting a concentration of the at least one cementitious material in the cement composition after the step of comparing; and
recalculating the compressive strength of the cement composition.

3 . The method of claim 2 wherein the step of adjusting comprises at least one of:
i. increasing a concentration of at least one cementitious material with a relatively higher reactivity index as compared to other cementitious materials if the calculated compressive strength is lower than the target compressive strength,
ii. increasing a concentration of at least one cementitious material with a relatively lower specific gravity as compared to other cementitious materials if the calculated compressive strength is lower than the target compressive strength,
iii. increasing a concentration of at least one cementitious material with a relatively lower reactivity index as compared to other cementitious materials if the calculated compressive strength is greater than the target compressive strength, or
iv. increasing a concentration of at least one cementitious material with a relatively higher specific gravity as compared to other cementitious materials if the calculated compressive strength is greater than the target compressive strength.

4 . The method of claim 1 wherein the model of compressive strength comprises at least one correlation between compressive strength and concentration of cementitious material.

5 . The method of claim 1 wherein the model of compressive strength has the form of:

ln


(
CS
)

=

ln


(
A
)

-

1.5
*

ln


(
B
)

*

1
-

ρ
S

ρ
D

ρ
S

ρ
W

-
1

where CS is compressive strength, A and B are constants dependent on concentrations of cementitious materials in the cement composition calculated by a regression model, ρ s is density of the cement composition, ρ d is density of a dry blend comprising the cementitious materials, and ρ w is a density of water.

6 . The method of claim 1 wherein the model of compressive strength has the form of:

CS
=

CS
0



(

w

c
eff

)

n

where


:





c
eff

=

c
cement

+

Σ




α
i



c
i

and where c cement is the mass fraction of Portland cement in a dry blend comprising the cementitious materials, a, is a reactivity index of component i in a dry blend comprising the cementitious materials, c, is the mass fraction of cementitious component i in the dry blend, w/c eff is water-to-cement ratio, CS is compressive strength, CS 0 is a compressive strength of a Portland cement composition where a water to cement ratio is 1, and n is a constant.

7 . The method of claim 6 wherein the reactivity index is calculated based at least in part on a correlation comprising constants, wherein the correlation has the general form of:
reactivity index=Π f ( p i )

where p i is a measurable physicochemical property of the cementitious component.

8 . The method of claim 1 wherein the model of compressive strength has the form of:
CS=ΣCS i

where CS i is a compressive strength contribution of component i in a dry blend comprising the cementitious materials.

9 . A system comprising:
a predictive model database comprising at least one model of compressive strength for a plurality of cementitious materials; and a computer system configured to:
accept an input of compressive strength and composition density;
query the predictive model database and select a model;
generate a cement composition, based at least in part on the selected model, compressive strength, and composition density; and
display the cement composition to a user.

10 . The system of claim 9 wherein the at least one model of compressive strength correlates concentration of cementitious material to compressive strength.

11 . The system of claim 9 wherein the at least one model of compressive strength has the form of:

ln


(
CS

Assignees

• Halliburton Energy Services Inc

Inventors

• Singh John Paul Bir
• Pang Xueyu
• Yerubandi Krishna Babu
• Pisklak Thomas Jason
• Morgan Ronnie Glen
• Jandhyala Siva Rama Krishna

Classifications

• C09K8/42 Primary

  Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells (compositions for plastering C09K8/50) · CPC title

• C04B2201/50

  for the mechanical strength · CPC title

• C04B2201/20

  for the density · CPC title

• C04B40/0032

  Controlling the process of mixing, e.g. adding ingredients in a quantity depending on a measured or desired value (B28C7/00 takes precedence) · CPC title

• C04B7/02

  Portland cement · CPC title