| Patents for E21B 37 - Methods or apparatus for cleaning boreholes or wells (5,129) |
|---|
| 10/29/1991 | US5060725 High pressure well perforation cleaning |
| 10/15/1991 | US5056599 Method for treatment of wells |
| 10/09/1991 | EP0450170A2 Well regeneration device |
| 10/09/1991 | CN1055219A Construction for hanging freely auxiliary gushing tube in deep well |
| 10/08/1991 | US5054557 Device for extracting a liquid out of a tube of great length |
| 10/01/1991 | US5052491 Oil tool and method for controlling paraffin deposits in oil flow lines and downhole strings |
| 09/19/1991 | WO1991014076A1 Well clearing and cleaning device |
| 09/17/1991 | CA1289008C Rod guide |
| 09/07/1991 | CA2037547A1 Method and apparatus for locating solvent injection apparatus within a natural gas wellbore |
| 09/05/1991 | WO1991013235A1 Device for delivering corrosion or deposition inhibiting agents into a well by means of an auxiliary delivery tube |
| 09/03/1991 | US5044439 Sodium (meth)acrylate, (meth)acrylamide copolymer |
| 08/22/1991 | WO1991012409A1 Process and device for removing incrustation deposit in fountains |
| 07/31/1991 | CN2081881U Wax cleaner for oil well |
| 07/23/1991 | US5033545 Conduit of well cleaning and pumping device and method of use thereof |
| 07/23/1991 | CA1286601C Wellbore cleanout apparatus and method |
| 07/20/1991 | WO1991011270A1 Cleaning device |
| 07/20/1991 | CA2074247A1 Cleaning device |
| 07/09/1991 | US5029644 Jetting tool |
| 07/02/1991 | US5028343 Inhibit Loss Of Catalytic Activity In Storage For An Amine-Mercaptan Mixture |
| 06/27/1991 | WO1991009205A1 Device and method for cleaning an underground well |
| 06/23/1991 | CA2032055A1 Oil tool and method for controlling paraffin deposits in flow lines and downhole strings |
| 06/18/1991 | US5024271 Permanent-magnet wax-proof device |
| 06/12/1991 | EP0431507A2 Apparatus and method for cleaning filtering gravel packs in water wells |
| 06/12/1991 | CN2078795U Prismatic low wear-resistance righting paraffin scraper |
| 06/12/1991 | CN1052166A Wash tool |
| 06/05/1991 | CN1051956A Downhole jetting tool |
| 05/30/1991 | WO1991007569A1 Method for finishing a well |
| 05/22/1991 | CN1051607A Method of well completion |
| 05/21/1991 | US5016712 Method and apparatus for locating solvent injection apparatus within a natural gas wellbore |
| 05/16/1991 | DE3844689C2 Cleaning contaminated ground in successive vertical operations |
| 05/15/1991 | EP0427424A2 Wash tool |
| 05/15/1991 | EP0427423A2 Downhole jetting tool |
| 05/15/1991 | EP0427371A1 Method of well completion |
| 05/15/1991 | CN1012627B Detachable permanent magnetic waxproof device for oil well |
| 05/09/1991 | CA2029531A1 Jetting tool |
| 05/09/1991 | CA2029530A1 Wash tool |
| 05/07/1991 | US5012866 Drill stem mud wiping apparatus |
| 04/10/1991 | EP0421822A2 Method and apparatus for single trip injection of fluid for well treatment and for gravel packing thereafter |
| 04/09/1991 | CA1282687C Enhanced diameter clean-out tool and method |
| 03/28/1991 | DE3931011A1 Well shaft filter cleaning for below ground filters - has tubes sunk parallel to shaft connected in pump circuit for forced cleaning with provision for adding materials to flow |
| 03/26/1991 | US5002139 Drilling tool |
| 03/19/1991 | US5000260 A pipe |
| 03/19/1991 | CA1281638C Pipe scraping device |
| 03/13/1991 | EP0417009A1 Device and installation for the cleaning of drains especially in an oil production well |
| 03/13/1991 | CN1011993B Cleaning device for internal surface of casing pipes |
| 03/05/1991 | CA1280883C Foaming acid-containing fluids |
| 02/26/1991 | US4995462 Dewaxing control apparatus for oil well |
| 02/26/1991 | US4995459 Rod guide/paraffin scraper |
| 02/22/1991 | CA2023640A1 Drill stem mud wiping apparatus |
| 02/12/1991 | US4991654 A sliding sleeve |
| 02/12/1991 | US4991653 Wash tool |
| 01/30/1991 | CN1048907A Hydrogen sulfide removing method |
| 01/30/1991 | CN1011432B Extracting method of special crude oil |
| 01/29/1991 | US4988389 Jet pump; injection of solvent |
| 01/22/1991 | US4986727 Pressure-operated oil and gas well swabbing device |
| 01/22/1991 | CA1279240C Process and product for sulfur dissolution |
| 01/02/1991 | CN2068581U 钻杆清洁器 Drill pipe cleaner |
| 12/26/1990 | CN2068146U Beam-pumping unit wax scraper |
| 12/26/1990 | CN2068145U Embedded core type drill rod mud scraper |
| 12/12/1990 | EP0402239A1 Device for extracting a liquid from a long pipe |
| 12/11/1990 | US4976318 Technique and apparatus for stimulating long intervals |
| 12/05/1990 | EP0400137A1 Dual wall well development tool |
| 11/28/1990 | CN2066485U Centrifugal sand cleaning device |
| 11/27/1990 | US4972904 Geothermal well chemical injection system |
| 11/06/1990 | US4967841 Horizontal well circulation tool |
| 10/24/1990 | CN1010114B Flushing method for hydrographic and engineering geological well drilling |
| 09/25/1990 | US4958683 Method and apparatus for treating wells |
| 08/28/1990 | US4951750 Method and apparatus for single trip injection of fluid for well treatment and for gravel packing thereafter |
| 08/22/1990 | CN1044844A Stabilized sulfur dissolving compositions |
| 08/21/1990 | US4949788 Well completions using casing valves |
| 08/16/1990 | EP0381853A2 Stabilized sulfur dissolving compositions |
| 08/09/1990 | CA2008561A1 Stabilized sulfur dissolving compositions |
| 08/07/1990 | US4945992 Injecting an aqueous solution of chlorine dioxide under pressure into a well |
| 07/31/1990 | US4944349 Combination downhole tubing circulating valve and fluid unloader and method |
| 07/04/1990 | EP0376422A2 Method of cleaning well shafts |
| 06/28/1990 | WO1990007048A1 Dual wall well development tool |
| 06/14/1990 | CA2005605A1 Dual wall well development tool |
| 05/17/1990 | DE3920800C1 Detoxifying soil in-situ - by introducing cleansing medium and vibrating using cylindrical chamber with 3 radial plate carrying tubes |
| 05/08/1990 | US4923011 Drill stem mud wiping apparatus |
| 05/01/1990 | US4921577 Method for operating a well to remove production limiting or flow restrictive material |
| 05/01/1990 | US4921046 Horizontal hole cleanup tool |
| 04/24/1990 | US4919204 Apparatus and methods for cleaning a well |
| 04/17/1990 | US4917183 Gravel pack screen having retention mesh support and fluid permeable particulate solids |
| 04/11/1990 | CN1041202A Detachable permanent magnetic waxproof device for oil well |
| 04/10/1990 | US4915176 Injecting an antiagglomerant to form a dispersion; petroleum oil and gas from ocean wells |
| 03/28/1990 | CN2055177U Switching type double insurance oil drainer |
| 03/27/1990 | US4911240 Self treating paraffin removing apparatus and method |
| 03/27/1990 | US4911239 Method and apparatus for removal of oil well paraffin |
| 03/27/1990 | CA1267079A1 Method for removal of flow restricting matter from hydrocarbon producing wells |
| 03/20/1990 | US4909325 Horizontal well turbulizer and method |
| 03/07/1990 | CN2054072U Apparatus for cleaning well |
| 02/27/1990 | US4903775 Well surging method and apparatus with mechanical actuating backup |
| 02/20/1990 | CA1265992A1 Method for drawing up special crude oil |
| 02/13/1990 | US4899821 Method and apparatus for servicing well casing and the like |
| 01/30/1990 | US4896726 Slip stream device |
| 01/30/1990 | US4896720 Method and system for cleaning well casing |
| 01/25/1990 | WO1990000668A1 Well backsurging apparatus and method |
| 01/24/1990 | EP0352215A2 Drilling tool |
| 01/17/1990 | CN1006460B Composition for inhibiting inorganic salt scale formation |
| 01/16/1990 | US4893684 Method of changing well fluid |