# US 11,306,555 B2 · Drill pipe with dissolvable layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,555 B2 - Document ID: US11306555B2 - Status: Granted - Kind: B2 - Application number: 16/838,876 - Filed: 2020-04-02 - Published: 2021-10-07 - Granted: 2022-04-19 - Earliest claimed: 2020-04-02 - Assignees: Saudi Arabian Oil Company - Applicants: Saudi Arabian Oil Company - Inventors: Ibrahim Abdullah Althowiqeb - Web page: https://patentgrep.com/patent/US11306555B2 ## CPC - E21B 17/00: Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; {Cables;} Casings; Tubings - E21B 31/002: {Destroying the objects to be fished, e.g. by explosive means} - E21B 17/006: {Accessories for drilling pipes, e.g. cleaners (wear protectors E21B17/10; handling drilling pipes E21B19/00; thread protectors B65D59/00)} - E21B 17/1064: {Pipes or rods with a relatively rotating sleeve} - E21B 29/02: by explosives or by thermal or chemical means {(freeing stuck objects by explosives E21B31/002)} - E21B 31/035: {controlling differential pipe sticking} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract Presented herein are apparatus and methods that alleviate incidence of stuck pipes in downhole environments. In some embodiments, the apparatus and methods described herein include a drill pipe for drilling operations including: a dissolvable layer deposited on a portion of an outer surface of the drill pipe; and a tunnel connected to the dissolvable layer. ## Claims ### Claim 1 A drill pipe for drilling operations, the drill pipe comprising: a top portion; a bottom portion; a center portion disposed between the top portion and the bottom portion; a dissolvable layer deposited on an outer surface of the center portion; and a tunnel extending longitudinally along the length of the center portion and fluidly connecting the top portion to the dissolvable layer, wherein the tunnel is disposed on the outer surface of the drill pipe, and within the dissolvable layer, so that the tunnel is in contact with the dissolvable layer. ### Claim 2 (depends on 1) The drill pipe of claim 1, wherein an outer diameter of the dissolvable layer is substantially equal to the outer diameters of the top portion and the bottom portion. ### Claim 3 (depends on 1) The drill pipe of claim 1, wherein the dissolvable layer comprises a material dissolvable by a dissolving solution comprising an acid. ### Claim 4 (depends on 3) The drill pipe of claim 3, wherein the dissolvable layer comprises a material selected from the group consisting of plastic, glass fiber, and combinations thereof. ### Claim 5 (depends on 3) The drill pipe of claim 3, wherein the acid is selected from the group consisting of hydrofluoric acid (HF), hydrobromic acid (HBr), hydroiodic acid (HI), hypochlorous acid (HClO), chlorous acid (HClO2), chloric acid (HClO3), perchloric acid (HClO4), hypobromic acid (HBrO), bromous acid (HBrO2), chloric acid (HBrO3), perbromic acid (HBrO4), hypoiodous acid (HIO), iodous acid (HIO2), iodic acid (HIO3), periodic acid (HIO4), hypofluorous acid (HFO), sulfuric acid (H2SO4), fluorosulfuric acid (HSO3F), nitric acid (HNO3), phosphoric acid (H3PO4), fluoroantimonic acid (HSbF6), fluoroboric acid (HBF4), hexafluorophosphoric acid (HPF6), chromic acid (H2CrO4), boric acid (H3BO3), and combinations thereof. ### Claim 6 (depends on 3) The drill pipe of claim 3, wherein the acid comprises HCl. ### Claim 7 (depends on 3) The drill pipe of claim 3, wherein a molarity of the dissolving solution is within a range from about 1 M to about 30 M. ### Claim 8 (depends on 3) The drill pipe of claim 3, wherein the dissolvable layer comprises CaCO3, wherein the dissolving solution comprises HCl, and wherein the dissolution process releases gas, thereby increasing the pressure in the borehole, and wherein the gas comprises carbon dioxide (CO2). ### Claim 9 (depends on 1) The drill pipe of claim 1, wherein the tunnel comprises a plurality of four (4) tunnels circumferentially spaced 90-degrees apart around the drill pipe, and wherein the dissolvable layer comprises CaCO3. ### Claim 10 (depends on 9) The drill pipe of claim 9, further comprising a channel, wherein the channel fluidly connects the dissolvable layer and the tunnel radially. ### Claim 11 (depends on 10) The drill pipe of claim 10, further comprising additional channels. ### Claim 12 (depends on 10) The drill pipe of claim 10, further comprising additional tunnel(s), thereby comprising 2, 3, 4, 5, or 6 tunnels, wherein the tunnels are parallel to each other, and wherein the drill pipe comprises at least one channel per tunnel. ### Claim 13 (depends on 1) The drill pipe of claim 1, wherein the dissolvable layer comprises CaCO3. ### Claim 14 (depends on 1) The drill pipe of claim 1, wherein a porosity of the dissolvable layer is within a range from about 10% to about 40%. ### Claim 15 (depends on 1) The drill pipe of claim 1, wherein a thickness of the dissolvable layer is within a range from about 1 mil to about 500 mils. ### Claim 16 (depends on 1) The drill pipe of claim 1, wherein the tunnel is at least one of helix-shaped, zigzag-shaped or sinusoidal, within the wall of the drill pipe. ### Claim 17 (depends on 1) The drill pipe of claim 1, wherein the dissolvable layer comprises at least one phenolic resin. ### Claim 18 (depends on 1) The drill pipe of claim 1, wherein the dissolvable layer remains connected to a fluid source, even if the drill pipe becomes stuck. ### Claim 19 A method for alleviating incidence of stuck pipe events, the method comprising: deploying a drill pipe in a downhole environment, the drill pipe comprising: a dissolvable layer deposited on a portion of an outer surface of the drill pipe, the dissolvable layer comprising CaCO3; and a tunnel connected to the dissolvable layer, initiating a drilling process; stopping the drilling process; and dissolving the dissolvable layer by supplying a dissolving solution through the tunnel, the dissolving solution comprising hydrochloric acid (HCl), wherein carbon dioxide (CO2) gas is released as a result of dissolving the dissolvable layer, thereby increasing the pressure within the downhole environment, and wherein the drill pipe becomes unstuck without having to deploy any tooling in the downhole environment. ### Claim 20 (depends on 19) The method of claim 19, further comprising circulating fluid, wherein a flow rate of dissolving fluid though the drill pipe is within about 10% of the flow rate of circulating fluid. ### Claim 21 (depends on 1) A drill pipe system for drilling operations comprising the drill pipe of claim 1, the drill pipe comprising a first drill pipe and a second drill pipe, wherein the tunnel of the first drill pipe is aligned with and fluidly connected to the tunnel of the second drill pipe such that dissolving fluid may be delivered from the top of the first drill pipe to the bottom of the second drill pipe. ### Claim 22 (depends on 21) The system of claim 21, wherein the dissolvable layer comprises CaCO3, and the dissolving fluid comprises an acid, such that the CaCO3 and acid produce a gas, thereby increasing the pressure in the downhole environment.