# US 2021/0340864 A1 · Mud pulser and method for operating thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0340864 A1 - Document ID: US20210340864A1 - Status: Published application - Kind: A1 - Application number: 16/863,512 - Filed: 2020-04-30 - Published: 2021-11-04 - Earliest claimed: 2020-04-30 - Assignees: China Petroleum & Chemical Corporation - Applicants: China Petroleum & Chemical Corporation - Inventors: Sheng ZHAN; Sam Seldon - Web page: https://patentgrep.com/patent/US20210340864A1 ## CPC - E21B 47/18: through the well fluid {, e.g. mud pressure pulse telemetry} - E21B 47/24: by positive mud pulses using a flow restricting valve within the drill pipe - E21B 17/006: {Accessories for drilling pipes, e.g. cleaners (wear protectors E21B17/10; handling drilling pipes E21B19/00; thread protectors B65D59/00)} - E21B 17/22: Rods or pipes with helical structure - E21B 21/12: using drilling pipes with plural fluid passages, e.g. closed circulation systems - E21B 34/16: Control means therefor being outside the borehole {(control systems for submerged well heads E21B33/0355)} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract A pulser for generating pressure pulses propagating through a column of drilling fluid in the drill string to the surface during drilling. The pulser may include a screen in the surface of a tubular housing to permit mud from the mud stream to enter into the pulser; an adjustable servo valve configured to receive the mud and including a removable servo poppet and a removable servo orifice member positioned in the tubular housing, wherein the adjustable servo valve is configured to allow the removable servo poppet and the removable servo orifice member to be replaced by another removable servo poppet and another removable servo orifice member to alter an inner diameter of an orifice of the adjustable servo valve to accommodate drilling conditions to increase a performance of the pulser generating pressure pulses for the mud stream returning to the surface. ## Claims ### Claim 1 A pulser for generating pressure pulses in a drilling fluid during a drilling operation, comprising: a tubular housing; a pressure compensation piston separating the tubular housing into a proximal portion and a distal portion; a motor resides in the proximal portion; a servo valve resides in the distal portion; a piston shaft coupled to the motor and extends through the pressure compensation piston into the distal portion, wherein the motor causes the poppet shaft to reciprocate along a longitudinal direction of the tubular housing; one or more metal screens affixed to a surface of the distal portion of the tubular housing, configured to allow the drilling fluid to enter the tubular housing; wherein the servo valve comprises a poppet detachably affixed to the poppet shaft and an orifice member having an orifice that allows the drilling fluid to pass, wherein a reciprocating motion of the poppet shaft causes the poppet to close or open the orifice, thereby stopping or releasing a flow of the drilling fluid through the pulser. ### Claim 2 (depends on 1) The pulser of claim 1, wherein each of the one or more metal screens includes a plurality of screen members positioned to form a plurality of slits to allow the drilling fluid to flow into the distal end of the tubular housing, wherein each of the plurality of slits is oriented so that a middle point of the slit is positioned distal to two ends of the slit. ### Claim 3 (depends on 1) The pulser of claim 1, further comprising an orifice housing disposed in the distal portion of the tubular housing, wherein the orifice member is detachably affixed to the orifice housing. ### Claim 4 (depends on 3) The pulser of claim 3, wherein the orifice in the orifice member has a diameter ranging from 0.2 inches to 0.5 inches, and the poppet has a size that matches the orifice. ### Claim 5 (depends on 1) The pulser of claim 1, wherein the orifice housing is detachably affixed to the tubular housing, wherein detaching the orifice housing from the tubular housing exposes the poppet so that the poppet is removable from the tubular housing. ### Claim 6 (depends on 1) The pulser of claim 1, further comprising a compression spring disposed in the distal portion of the tubular housing and exerts a force against the pressure compensation piston, wherein, during operation, the proximal portion is filled with a lubricant and the distal portion is filled with the drilling fluid, wherein the pressure compensation piston moves along the longitudinal direction of the tubular housing in response to a pressure difference between the lubricant and the drilling fluid. ### Claim 7 (depends on 6) The pulser of claim 6, wherein the pressure compensation piston includes a spiral pattern on an outer surface of the pressure compensation piston and the inner surface of the pressure compensation piston. ### Claim 8 (depends on 7) The pulser of claim 7, wherein the spiral pattern includes a plurality of spiral grooves of a rectangular shape, wherein the lubricant fills the spiral grooves. ### Claim 9 (depends on 8) The pulser of claim 8, wherein each of the spiral grooves is about 1/16 inches wide and about 1/32 inches deep, and wraps around the inner diameter and the outer diameter at approximately one revolution for every two inches of a length of the pressure compensation piston. ### Claim 10 (depends on 6) The pulser of claim 6, further comprising a pressure balance plate disposed between the pressure compensation piston and the compression spring. ### Claim 11 (depends on 10) The pulser of claim 10, further comprises a first sealing ring that seals a gap between the pressure compensation piston and the tubular housing and a second sealing ring that seals a gap between the pressure compensation piston and the piston shaft. ### Claim 12 (depends on 11) The pulser of claim 11, wherein the first sealing ring is a first X-ring disposed about an outer surface of the pressure compensation piston and the second sealing ring is a second X-ring disposed about an inner surface of the pressure compensation piston. ### Claim 13 (depends on 1) A method to prepare the pulser of claim 1 for operation, comprising: estimating a depth of the pulser in a bore hole; estimating an amplitude of pressure pulses required for the pressure pulses to propagate from the estimated depth to the surface; selecting a diameter of the orifice and the poppet required for generating pressure pulses of the estimated amplitude; and installing the orifice member having the selected orifice of and the poppet in the pulser. ### Claim 14 (depends on 15) The method of claim 15, wherein the installation step comprises: removing an orifice housing from the pulser; affixing the poppet to the poppet shaft; affixing the orifice member to the orifice housing; and installing the orifice housing with the orifice member to the pulser. ### Claim 15 (depends on 14) The method of claim 14, wherein the orifice member is selected from a plurality of orifice members having a common outer diameter, and each of the plurality of orifice members has an orifice of different diameter. ### Claim 16 (depends on 15) The method of claim 15, wherein the orifice in each of the plurality of orifice members has a diameter in ranging from 0.2 inches to 0.5 inches. ### Claim 17 (depends on 13) The method of claim 13, wherein the estimated amplitude of the pressure pulses is about 500 psi and the selected orifice has a diameter of 0.5 inches.