Permeable cements
AssigneeSchlumberger Technology Corporation
InventorsSamuel Danican, Bruno Drochon, Simon James, Beilin Ding
Life of this patent
Estimating the term…
Abstract
A permeable cement composition comprises an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase, such as oil or gas, and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
Claims26
1 A permeable cement composition, comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
2 A cement composition as claimed in claim 1, wherein the hollow particulate material comprises micro-spheres or cenospheres.
3 A cement composition as claimed in claim 1 or 2, wherein the hollow particulate material has particles sizes in the range 350-50 microns.
4 A cement composition as claimed in any of claims 1-3, wherein the hollow particulate material is present in an amount of 10%-60% by volume of dry materials used to make the slurry.
5 A cement composition as claimed in any preceding claim, wherein the dispersed fluid phase comprises air, nitrogen or oil.
6 A cement composition as claimed in any preceding claim, wherein the cement comprises Portland cement, pozzolanic material, blast furnace slag, fly ash, pozzolana, calcined clays, high-alumina cements, plaster, Sorel cement, or activated pozzolanic cements.
7 A cement composition as claimed in any preceding claim, wherein the slurry comprises solid materials including a combination of at least two of a fine particulate material having particle sizes in the range 0.1-10 micron, a medium particulate material having particle sizes in the range 20-60 micron and a coarse particles having particle sizes in the range 100-800 micron.
8 A cement composition as claimed in claim 7, wherein the fine particulate material comprises micro-cement.
9 A cement composition as claimed in claim 7, wherein the coarse particulate material comprises large particle size cement.
10 A cement composition as claimed in any of claims 7-9, wherein the hollow particulate material comprises the medium or coarse particulate material.
11 A cement composition as claimed in any of claims 7-10, wherein the coarse particulate material is present in an amount of 30%-80% by volume of dry materials used to make the slurry.
12 A cement composition as claimed in claim 11, wherein the coarse particulate material is present in an amount of 30%-60% by volume of dry materials used to make the slurry.
13 A cement composition as claimed in any of claims 7-12, wherein the medium particulate material is present in an amount of 10%-90% by volume of dry materials used to make the slurry.
14 A cement composition as claimed in claim 13, wherein the medium particulate material is present in an amount of 30%-60% by volume of solid material used to make the slurry.
15 A cement composition as claimed in any of claims 7-14, wherein the fine particulate material is present in an amount of up to 40% by volume of dry materials used to make the slurry.
16 A cement composition as claimed in claim 15, wherein the fine particulate material is present in an amount of about 10% by volume of dry materials used to make the slurry.
17 A cement composition as claimed in any preceding claim, wherein the slurry comprises a liquid fraction in the range 38%-50% by volume of the slurry when the dispersed phase is a gas.
18 A cement composition as claimed in any of claims 1-16, wherein when the dispersed phase comprises oil, the slurry comprises 38%-50% by volume of an aqueous phase and 40%-60% by volume of the total of oil.
19 A cement composition as claimed in any preceding claim, wherein the slurry further comprises a degradable surfactant.
20 A cement composition as claimed in claim 19, wherein the degradable surfactant comprises an ethoxylated castor oil.
21 A cement composition as claimed in any of claims 1-18, wherein the slurry further comprises a surfactant with a cloud point.
22 A method of remedial treatment of voids behind casing in a borehole, comprising pumping a cement slurry into the void and allowing it to set, the cement slurry comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
23 A method of completing a well, comprising pumping a cement slurry into an annulus around a casing, screen or slotted liner placed in a well and allowing it to set, the cement slurry comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
24 A method of preventing sand production from an underground formation into a well, comprising pumping a cement slurry into a region adjacent the formation and allowing it to set, the cement slurry comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
25 A method of replacing eroded cement behind a casing in a well, comprising pumping a cement slurry into the region of the eroded cement and allowing it to set, the cement slurry comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.
26 A method of selectively producing oil from an oil and water producing formation, comprising pumping a cement slurry into or adjacent to a producing formation, allowing the cement to set, so as to produce fluid from the reservoir with an oil water ratio higher than would normally be possible from an untreated formation, the cement slurry comprising an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids which together with the dispersed phase create a permeable structure in the cement.