# US 2013/0153796 A1 · Underground Annular Blowout Preventer and Assembly Process Thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153796 A1 - Document ID: US20130153796A1 - Status: Published application - Kind: A1 - Application number: 13/818,092 - Filed: 2012-02-21 - Published: 2013-06-20 - Earliest claimed: 2011-05-26 - Assignees: Southwest Petroleum University - Inventors: Qingyou Liu; Wei Li - Web page: https://patentgrep.com/patent/US20130153796A1 ## CPC - E21B 33/06: Blow-out preventers {, i.e. apparatus closing around a drill pipe, e.g. annular blow-out preventers (rotating blow-out preventers E21B33/085)} - E21B 21/10: Valve arrangements in drilling-fluid circulation systems - E21B 33/10: in the borehole {(sealing the junction between main bore and laterals E21B41/0042)} - E21B 34/10: operated by control fluid supplied from outside the borehole - Y10T 29/49412: with assembly, disassembly or composite article making - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An underground annular blowout preventer, which belongs to the technical field of underground blowout prevention, includes an upper joint and a lower joint are sleeved outside a central barrel. The lower end of the central barrel is fixedly connected with the lower joint. The lower end of the upper joint is sleeved on the inner side of the upper end of the lower joint. The upper joint is matched with the lower joint through a spline. The lower end of the upper joint can freely move relative to the lower joint along a spline pair. At least one rubber barrel is sleeved on the outer side of the upper joint. The rubber barrel can be extruded and expanded by the upper joint and the lower joint. The underground annular blowout preventer of the present invention can transmit large torque, has a simple structure, long service life, is convenient to use, and can be repeatedly used. The underground annular blowout preventer is used in coordination with a check valve of a near drill in the well drilling process, so that quick sealing of a well can be ensured, and well blowout accidents can be effectively prevented. A pipe column is lowered to seal the well and is lifted to open the well, and the inside of the drill rod is in communication with an annular space after the well is sealed, which facilitates replacement for heavy mud lubrication operations. ## Claims ### Claim 1 An underground annular blowout preventer, comprising an upper joint, a lower joint, a central barrel, and a rubber barrel, wherein said upper joint and said lower joint are sleeved outside said central barrel, wherein the lower end of said central barrel is fixedly connected with said lower joint, wherein the lower end of said upper joint is sleeved on the inner side of the upper end of said lower joint, wherein said upper joint is matched with said lower joint through a spline, wherein at least one rubber barrel is sleeved on the outer side of said upper joint and said rubber barrel can be extruded and expanded by said upper joint and said lower joint; a first flow guiding hole is set on said central barrel and a second flow guiding hole is set on said upper joint, a sealing member is set between inner wall of said upper joint and outer wall of said central barrel, periphery of said first flow guiding hole and periphery of said second flow guiding hole are sealed by said sealing member, and said first flow guiding hole and said second flow guiding hole are in butt joined with each other when said upper joint moves downwards, Is wherein a first check valve is set inside said first flow guiding hole, and/or a second check valve is set inside said second flow guiding hole, wherein a spring ejector is set on the inner side of the upper end of said upper joint, wherein outer side of said central barrel is close to said upper joint is provided with multiple moving grooves which are matched with said spring ejector, wherein the ejector on said spring ejector is in sliding cooperation with each of said moving grooves, wherein the inner wall of said central barrel is provided with an installation auxiliary hole. ### Claim 2 (depends on 1) The underground annular blowout preventer, according to claim 1, wherein said upper joint comprises of an upper joint component and an inner sleeve which are fixedly connected with each other, wherein said spring ejector is set inside said upper joint component and said second flow guiding hole is set on said upper joint component, wherein the lower end of said inner sleeve is sleeved on said inner side of said upper end of said lower joint and said inner sleeve is in clearance fit with said lower joint through a spline, wherein said rubber barrel is sleeved outside of said inner sleeve and can be extruded and expanded by said upper joint component and said lower joint. ### Claim 3 (depends on 1) The underground annular blowout preventer, according to claim 1, wherein said upper joint comprises of an upper connector, an upper external sleeve, and said inner sleeve which are fixedly connected with each other, wherein said spring ejector is set inside said upper connector, and said second flow guiding hole is set on said upper external sleeve, wherein said lower end of said inner sleeve is sleeved on said inner side of said upper end of said lower joint, and said inner sleeve is in clearance fit with said lower joint through a spline, wherein said rubber barrel is sleeved outside of said inner sleeve and can be extruded and expanded by said upper external sleeve and said lower joint. ### Claim 4 (depends on 1) The underground annular blowout preventer, according to claim 1, wherein outside of said central barrel is provided with a convex shoulder which forms a whole structure with said central barrel, a thrust bearing is sleeved outside of said central barrel, and said thrust bearing is between said convex shoulder outside of said central barrel and said upper end surface of said inner sleeve. ### Claim 5 (depends on 1) The underground annular blowout preventer, according to claim 1, wherein said central barrel comprises of a support sleeve sleeved and fixed outside of the central barrel body, wherein said support sleeve is of a whole structure or made of multiple pieces, and said thrust bearing which is between said support sleeve and said upper end surface of said inner sleeve is sleeved outside of said central barrel. ### Claim 6 (depends on 1) The underground annular blowout preventer, according to claim 1, wherein said lower joint mainly comprises of a lower connector and a lower external sleeve which are fixedly connected with each other, wherein the spline in said lower joint is inside said external sleeve which is fixedly connected with said lower end of said central barrel. ### Claim 7 An assembly method of an underground annular blowout preventer, comprising the following steps: S701, fixing the inner sleeve, embedding multiple spacer rings and the rubber barrel outside of the inner sleeve along the thread direction at the upper end of the inner sleeve, such that said spacer rings and said rubber barrel are limited at the upper right side of the convex shoulder at the middle of said inner sleeve; S702, embedding the thrust bearing inside the upper external sleeve from the lower end thereof, and fixedly connecting the lower end of said upper external sleeve and said upper end of said inner sleeve; S703, embedding the first check valve and the second check valve separately on the side walls of the central barrel and said upper external sleeve and tightening to a predetermined torque, embedding the sealing member to the relevant position of said central barrel and mounting said central barrel from top of said upper external sleeve and said inner sleeve; S704, embedding the lower joint to the outside of said central barrel and said inner sleeve, stretching the outward expanding tool to the inner side of said central barrel and blocking the tool in the installation auxiliary hole, and fixing said lower joint while rotating said central barrel, or fixing said central barrel while rotating said lower joint so as to tighten the thread pair between the lower end of said central barrel and said lower joint to the predetermined torque; and S705, embedding the spring ejector inside the upper connector, inserting said upper connector into said central barrel along the outer wall thereof, fixing said upper external sleeve while rotating said upper connector, or fixing said upper connector while rotating said upper external sleeve so as to tighten the thread pair between said upper connector and said upper external sleeve to the predetermined torque, such that the ejector on said spring ejector slides into the upper moving groove of said central barrel during the downward movement process of said upper connector. ### Claim 8 (depends on 7) The assembly method, according to claim 7, further comprising the following steps: S801, fixing said inner sleeve, embedding said multiple spacer rings and said rubber barrel outside of said inner sleeve along the thread direction on the upper end of said inner sleeve, such that said spacer rings and said rubber barrel are limited above the convex shoulder at the middle of said inner sleeve; S802, mounting the first check valve on the support sleeve and embedding said spring ejector to the inner wall of the upper joint component, embedding said support sleeve inside said upper joint component from the lower end thereof and embedding said thrust bearing inside said upper joint component from said lower end thereof, and fixedly connecting said lower end of said upper joint component and said upper end of said inner sleeve; S803, embedding the central barrel body into said inner sleeve from the lower end thereof and passing through said support sleeve, fixedly connecting said central barrel body and said support sleeve and embedding the second check valve to said inner wall of said upper joint component; and S804, embedding said lower joint into said central barrel body along the lower end of said central barrel body and the external spline end of said internal sleeve, stretching the outward expanding tool to inner side of said central barrel body and blocking the tool into the installation auxiliary hole, fixing said lower joint while rotating said central barrel body, or fixing said central barrel body while rotating said lower joint, so as to tighten the thread pair between said central barrel body and said lower joint to the predetermined torque, such that the ejector on said spring ejector slides into the upper moving groove of said central barrel body during the downward movement process of said upper joint component. ### Claim 9 (depends on 7) The assembly method, according to claim 7, further comprising the following steps: S901, embedding said first check valve into the first flow guiding hole on said support sleeve which is made by splicing multiple pieces, embedding said thrust bearing which is made by splicing multiple pieces into the cavity of said upper joint and embedding said support sleeve into the cavity of said upper joint over said thrust bearing; S902, embedding said spring ejector into said inner wall of said upper end of said upper joint, sleeving said rubber sleeve and said spacer ring in order on the middle part outside said upper joint, embedding said central barrel body into said upper joint from the lower end thereof and passing through said support sleeve, fixedly connecting said central barrel body and said support sleeve, embedding said second check valve into said second flow guiding hole on said upper joint; and S903, embedding said lower joint along the external spline end at said lower end of said central barrel body and said lower end of said upper joint, stretching the outward expanding tool to inner side of said central barrel body and blocking the tool into the installation auxiliary hole, fixing said lower joint while rotating said central barrel body, or said the central barrel body while rotating said lower joint, so as to tighten the thread pair between the lower end of said central barrel body and said lower joint to the predetermined torque, such that the ejector on said spring ejector slides into said upper moving groove of said central barrel body during the downward movement process of said upper joint.