# US 12,215,580 B2 · Differential pressure sliding sleeve, and oil and gas well fracturing construction method using same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,580 B2 - Document ID: US12215580B2 - Status: Granted - Kind: B2 - Application number: 18/563,069 - Filed: 2021-06-10 - Published: 2024-07-04 - Granted: 2025-02-04 - Earliest claimed: 2021-06-10 - Assignees: China Petroleum & Chemical Corporation; Sinopec Southwest Oil & Gas Company - Applicants: China Petroleum & Chemical Corporation; Sinopec Southwest Oil & Gas Company - Inventors: Shunqu Hu; Yongmao Lin; Wei Zhao; Wei Lei; Zhi Xie; Zhimin Hou; Chen Chen; Qiang Wang; Dan Hu; Jingyu Cui - Web page: https://patentgrep.com/patent/US12215580B2 ## CPC - E21B 43/26: by forming crevices or fractures - E21B 34/08: responsive to flow or pressure of the fluid obtained (E21B34/10 takes precedence) - E21B 34/14: operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools {(E21B34/066 takes precedence)} - E21B 2200/06: Sleeve valves - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A differential-pressure sliding sleeve has an outer cylinder with a flow guiding hole being provided in a wall of the outer cylinder, an inner cylinder arranged in an inner cavity of the outer cylinder, an upper joint extending into the outer cylinder and fixedly connected to an upper end of the outer cylinder, a lower joint extending into the outer cylinder and fixedly connected to a lower end of the outer cylinder, and a dissolvable carrier ring arranged between the lower joint and the inner cylinder. An area of the axial upper end surface of the inner cylinder is greater than that of an axial lower end surface thereof, so that the working fluid generates a pressure difference to provide downward pressure for the inner cylinder, which moves downward under the pressure after the carrier ring is dissolved to open the flow guiding hole. ## Claims ### Claim 1 A differential-pressure sliding sleeve, comprising: an outer cylinder, with a flow guiding hole being provided in a wall of the outer cylinder; an inner cylinder arranged in an inner cavity of the outer cylinder, wherein in an initial state, the inner cylinder and the outer cylinder are fixed to each other to close the flow guiding hole; an upper joint extending into the inner cavity of the outer cylinder and fixedly connected to an upper end of the outer cylinder, wherein a clearance is formed between a lower end surface of the upper joint and an axial upper end surface of the inner cylinder; a lower joint extending into the inner cavity of the outer cylinder and fixedly connected to a lower end of the outer cylinder; and a carrier ring arranged in the inner cavity of the outer cylinder and between the lower joint and the inner cylinder, the carrier ring being dissolvable under an action of working fluid, wherein an area of the axial upper end surface of the inner cylinder is greater than that of an axial lower end surface thereof, so that the working fluid generates a pressure difference between the axial upper and lower end surfaces of the inner cylinder to provide a downward pressure for the inner cylinder, which moves downward under the pressure after the carrier ring is dissolved to open the flow guiding hole, wherein the flow guiding hole is filled with a filler, a protective element is arranged radially outside of the filler, at least one guiding hole is arranged on the protective element, and wherein the size of the at least one guiding hole is smaller than that of the flow guiding hole. ### Claim 2 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein an upper end portion of the inner cylinder is provided with an annular boss extending radially outward, so that the area of the axial upper end surface of the inner cylinder is greater than that of the axial lower end surface thereof. ### Claim 3 (depends on 2) The differential-pressure sliding sleeve according to claim 2, wherein an inner surface of the outer cylinder is provided with a shoulder portion extending radially inward, wherein an outer diameter of the annular boss is the same as an inner diameter of the outer cylinder, and an inner diameter of the shoulder portion is the same as an outer diameter of the inner cylinder. ### Claim 4 (depends on 3) The differential-pressure sliding sleeve according to claim 3, wherein an axial length of the annular boss is less than an axial distance from an axial upper end surface of the shoulder portion to the flow guiding hole. ### Claim 5 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the carrier ring is made of magnesium aluminum alloy, polytetrafluoroethylene, degradable plastic, or degradable ceramic material. ### Claim 6 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the filler is selected from a group consisting of viscous liquid, lubricating grease, and resin. ### Claim 7 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the protective element is fixed to the outer cylinder through adhesion or welding. ### Claim 8 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the at least one guiding hole corresponds to a center of the flow guiding hole. ### Claim 9 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the at least one guiding hole is an elongated slit, with a circular through hole being provided at each end of the slit. ### Claim 10 (depends on 1) The differential-pressure sliding sleeve according to claim 1, wherein the flow guiding hole comprises two steps formed on an outer wall of the outer cylinder and opposite to each other axially, the protective element being placed on the two steps. ### Claim 11 (depends on 1) The differential-pressure sliding sleeve according to claim 1, twherein a clearance in communication with the flow guiding hole is provided between the outer cylinder and the inner cylinder, and outside of each axial end of the flow guiding hole. ### Claim 12 (depends on 11) The differential-pressure sliding sleeve according to claim 11, wherein the clearance is an enlarged hole formed on the inner wall of the outer cylinder, wherein the enlarged hole comprises a sloping surface, so that the clearance narrows in a direction away from the flow guiding hole. ### Claim 13 (depends on 1) An oil and gas well fracturing construction method using the differential pressure sliding sleeve according to claim 1, comprising: connecting the differential-pressure sliding sleeve to a string, which is then lowered into a fracturing formation in a wellbore; injecting working fluid into the string from a wellhead, so that the carrier ring is dissolved under the action of the working fluid; building up pressure in the wellbore, so that the inner cylinder generates a downward pressure under the action of the working fluid, and moves downward after the pressure reaches a predetermined pressure value, thereby opening the flow guiding hole; and communicating the string with the fracturing formation to perform fracturing construction.