# US 7,743,830 B2 · Controlling the pressure within an annular volume of a wellbore > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,743,830 B2 - Document ID: US7743830B2 - Status: Granted - Kind: B2 - Application number: 12/249,852 - Filed: 2008-10-10 - Published: 2009-05-28 - Granted: 2010-06-29 - Earliest claimed: 2005-11-18 - Assignees: Chevron U.S.A. Inc.; Los Alamos National Security, LLC - Inventors: Robert E. Hermes; Manuel E. Gonzalez; Brian C. Llewellyn; James B. Bloys - Web page: https://patentgrep.com/patent/US7743830B2 ## CPC - E21B 33/13: Methods or devices for cementing, for plugging holes, crevices or the like - C09K 8/42: Compositions for cementing, e.g. for cementing casings into boreholes; Compositions for plugging, e.g. for killing wells (compositions for plastering C09K8/50) - E21B 36/00: Heating, cooling or insulating arrangements for boreholes or wells, e.g. for use in permafrost zones - Y10S 507/902: Controlled release agent - Y10T 137/0391: Affecting flow by the addition of material or energy - Y10T 137/0396: Involving pressure control - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated. ## Claims ### Claim 1 A process for controlling the pressure within a confined volume comprising: a) providing a volume containing a first fluid having a first pressure and a first temperature within the volume; b) replacing at least a portion of the first fluid within the volume with a second fluid comprising at least one anhydrous inorganic material; c) sealing the volume to produce a confined volume; d) heating the fluid within the confined volume, such that the fluid is at a second pressure and at a second temperature; wherein the second fluid is preselected such that the second pressure is lower than had the confined volume contained the first fluid only at the second temperature. ### Claim 2 (depends on 1) The process according to claim 1 wherein the volume is an annular volume. ### Claim 3 (depends on 1) The process according to claim 1 wherein the annular volume is described by two concentric casing strings within a wellbore. ### Claim 4 (depends on 1) The process according to claim 1, wherein the first temperature is in the range of from 0° F. to 100° F. ### Claim 5 (depends on 1) The process according to claim 1, wherein the second temperature is in the range of 50° F. to 300° F. ### Claim 6 (depends on 5) The process according to claim 5, wherein the second temperature is in the range of 125° F. to 250° F. ### Claim 7 (depends on 1) The process according to claim 1, wherein the fluid within the confined volume of step (c) is at the first pressure and at the first temperature. ### Claim 8 (depends on 1) The process according to claim 1, wherein the first pressure is the maximum pressure of the first fluid within the volume of step (a), and wherein the second pressure is the maximum pressure of the fluid within the volume of step (d). ### Claim 9 (depends on 1) The process according to claim 1, wherein the first pressure of the fluid at the first temperature within the volume of step (a) is at a selected location within the volume, and wherein second pressure of the fluid at the second temperature within the volume of step (d) is at the selected location within the volume. ### Claim 10 (depends on 1) The process according to claim 1, wherein the anhydrous inorganic material is selected from the group consisting of calcium sulfate, barium oxide, calcium oxide, zeolite 3A, zeolite 4A, zeolite 13X and zeolite Y. ### Claim 11 (depends on 1) The process according to claim 1, wherein the at least one anhydrous inorganic material is encapsulated in a slowly soluble polymer. ### Claim 12 (depends on 11) The process according to claim 11, wherein the slowly soluble polymer is selected from the group consisting of poly(vinylalcohol), carboxymethyl cellulose and gelatin. ### Claim 13 A process for controlling the pressure within the casing structure of a wellbore, comprising: a) providing an annular volume described by two casing strings within a wellbore and containing a first fluid having a first pressure and a first temperature at a selected location within the annular volume; b) replacing at least a portion of the first fluid within the annular volume with a second fluid comprising at least one anhydrous inorganic material; c) sealing the annular volume to produce a confined volume; d) heating the fluid within the confined volume, such that the fluid at the selected location is at a second pressure and at a second temperature; wherein the second fluid is preselected such that the second pressure at the selected location is lower than the pressure at the selected location within the confined volume would have been had the confined volume contained the first fluid only at the second temperature. ### Claim 14 (depends on 13) The process according to claim 13, wherein the second pressure is no more than 50% higher than the first pressure. ### Claim 15 (depends on 13) The process according to claim 13, wherein the second pressure is no more than 30% higher than the first pressure. ### Claim 16 (depends on 13) The process according to claim 13, wherein the second pressure is no more than 15% higher than the first pressure. ### Claim 17 (depends on 13) The process according to claim 13, wherein the second pressure is equal to the first pressure. ### Claim 18 A process for controlling the pressure within the casing structure of a wellbore, comprising: a) providing an annular volume described by two casing strings within a wellbore and containing a first fluid having a first maximum pressure at a first temperature within the annular volume; b) replacing at least a portion of the first fluid within the annular volume with a second fluid comprising at least one anhydrous inorganic material; c) sealing the annular volume to produce a confined volume; d) heating the fluid within the confined volume to an elevated temperature relative to the first temperature, such that at least a portion of the fluid is at a second maximum pressure; wherein the second fluid is preselected such that the second maximum pressure is lower than the maximum pressure within the confined volume would have been had the confined volume contained the first fluid only at the elevated temperature. ### Claim 19 A process for controlling the pressure within a confined volume comprising: a) providing at a first pressure and at a first temperature a volume containing a first fluid and a second fluid comprising at least one anhydrous inorganic material; b) sealing the volume to produce a confined volume; c) heating the first fluid and the second fluid within the confined volume, such that the first fluid and the second fluid are at a second pressure and at a second temperature; wherein the second fluid is preselected such that the second pressure is lower than had the confined volume contained the first fluid only at the second temperature. ### Claim 20 A process for controlling the pressure within an annular volume within a wellbore comprising: a) filling the annular volume with a first fluid; b) replacing at least a portion of the first fluid with a second fluid comprising an anhydrous inorganic material, within the annular volume; and c) sealing the annular volume. ### Claim 21 (depends on 20) The process according to claim 20, wherein the anhydrous inorganic material is selected from the group consisting of calcium sulfate, barium oxide, calcium oxide, zeolite 3A, zeolite 4A, zeolite 13X and zeolite Y. ### Claim 22 (depends on 20) The process according to claim 20, wherein the anhydrous inorganic material is selected from the group consisting of a zirconium tungstate and a zirconium molybdate, the anhydrous inorganic material having a negative coefficient of thermal expansion.