Work method to design extended life slurries

Patent metadata

Field	Value
Publication number	US-11577997-B2
Application number	US-202016923897-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Jul 8, 2020
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

First claim

What is claimed is:

1. A method of preparing a cement comprising:
(a) defining engineering parameters of a proposed cement slurry, wherein the engineering parameters comprise at least a density requirement, a compressive strength requirement, and a storage time requirement;
(b) selecting at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a cement slurry formed from the cement, the at least one supplementary cementitious material, and the water meet or exceed the density requirement;
(c) calculating a compressive strength of the cement slurry using a model of compressive strength, wherein the model of compressive strength includes a model element of sensitivity to change in water content in the cement slurry, wherein the model element of sensitivity to change in water amount in the cement slurry comprises an exponential term, a power law term, and/or a polynomial term relating an effect of water content in the cement slurry to compressive strength;
(d) comparing the compressive strength of the cement slurry to the compressive strength requirement and either repeating steps (b)-(d) if the compressive strength does not meet or exceed the compressive strength requirement or performing step (e) if the compressive strength meets or exceeds the compressive strength requirement;
(e) calculating a storage time of the cement slurry, using a storage time mode, wherein the model of storage time includes a model element of sensitivity to change in water content in the cement slurry, wherein the model element of sensitivity to change in water amount in the cement slurry comprises an exponential term, a power law term, and/or a polynomial term relating an effect of water content in the cement slurry to storage time;
(f) comparing the storage time to the storage time requirement and repeating steps (b)-(f) if the storage time does not meet or exceed the storage time requirement, or performing step (g) if the compressive strength meets or exceeds the required compressive strength; and
(g) preparing the cement slurry.

2. The method of claim 1 wherein the cement is selected from the group consisting of Portland cements, pozzolana cements, gypsum cements, high alumina content cements, silica cements, and combinations thereof.

3. The method of claim 1 wherein the at least one supplementary cementitious material is selected from the group consisting of fly ash, blast furnace slag, silica fume, pozzolans, kiln dust, clays, and combinations thereof.

4. The method of claim 1 wherein the engineering parameters further comprise wellbore temperature, a lime to silica ratio requirement, and wherein the step of selecting a cement and mass fraction thereof and at least one supplementary cementitious material and mass fraction thereof comprises:
selecting a first cement based at least in part on the wellbore temperature and a cement reactivity trend, wherein the cement reactivity trend comprises a correlation of cement reactivity with temperature;
selecting at least a first supplementary cementitious material based at least in part on wellbore temperature, supplementary cementitious material reactivity, temperature sensitivity of reactivity, and water requirement of supplementary cementitious material; and
calculating a silica content and a lime content for each of the first cement and the at least the first supplementary cementitious material and determining an additional amount of lime required to meet the lime to silica ratio requirement.

5. The method of claim 1 wherein the engineering parameters further comprise temperature and wherein the step of calculating the compressive strength comprises the following equation:

CS
=

CS
0

⁡

(

water

Σ
i

⁢

α
i

⁢

m
i

)

n

⁢

exp
⁡

(

-

E

eff
,
TT

R

⁢

(

1

T
ref

-

1
T

)

)

where CS 0 is the compressive strength of a Portland cement at a desired temperature when

water
Portland

=
1

,

water is a mass fraction of water, α i is a constant that characterizes reactivity of blend material i, m i is a mass fraction of component i, n is a measure of sensitivity to change in water content, E eff,TT is an effective activation energy, R is the universal gas constant, T ref is a reference temperature where effective activation energy is measured or calculated at, and T is the temperature.

6. The method of claim 1 wherein the engineering parameters further comprise temperature and wherein the step of calculating the storage time of the slurry comprises the following equation:

Storage
⁢

⁢
Time

=

S
⁢

T
0

⁡

(

water
blend

)

n

⁢

∑
i

⁢

Assignees

• Halliburton Energy Services Inc

Inventors

• Jandhyala Siva Rama Krishna
• Singh John Paul Bir
• Pisklak Thomas Jason
• Pineda Claudia Carmen

Classifications

• C04B28/02 Primary

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B28/14 Primary

  containing calcium sulfate cements {(gypsum-paper plates E04C)} · CPC title

• C09K8/467

  containing additives for specific purposes · CPC title

• E21B33/16

  using plugs for isolating cement charge; Plugs therefor {(stage cementing E21B33/146; spacer compositions C09K8/424)} · CPC title

• C09K8/46

  containing inorganic binders, e.g. Portland cement · CPC title