| Patents for E21B 21 - Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (13,780) |
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| 12/09/1997 | US5695009 Downhole oil well tool running and pulling with hydraulic release using deformable ball valving member |
| 12/09/1997 | CA2104559C Blended drilling fluid thinner |
| 12/04/1997 | WO1997045623A1 System and method for placement and retrieval of a subsurface diverting tool used in drilling and completing wells |
| 11/27/1997 | WO1997044565A1 Downhole apparatus |
| 11/27/1997 | WO1997044405A1 Clay-free biodegradable wellbore fluid and method for using said fluid |
| 11/27/1997 | CA2254920A1 Clay-free biodegradable wellbore fluid and method for using said fluid |
| 11/26/1997 | EP0808987A2 Hydraulic downhole hammer |
| 11/25/1997 | US5690811 Method for extracting oil from oil-contaminated soil |
| 11/25/1997 | US5690177 Fill valve |
| 11/23/1997 | CA2177088A1 Positive pressure release valve |
| 11/20/1997 | DE19647575A1 Drilling machine with suction etc wall ports |
| 11/18/1997 | US5687792 Drill pipe float valve and method of manufacture |
| 11/13/1997 | WO1997042395A1 Closed loop fluid-handling system for use during drilling of wellbores |
| 11/13/1997 | WO1997041972A1 Continuous belt drilling mud separation system |
| 11/11/1997 | US5685380 Reverse circulation down-the-hole drill |
| 11/06/1997 | WO1997041332A1 Flow diverter ring for a rotary drill bit and method |
| 11/06/1997 | DE19616979A1 Safety device for forced removal of material from underground pipes |
| 11/04/1997 | US5682957 Water separator for a down hole drill |
| 11/04/1997 | US5682952 Extendable casing circulator and method |
| 10/30/1997 | DE19616751A1 Counterboring drill |
| 10/30/1997 | CA2175296A1 Flow pulsing method and apparatus for the increase of the rate of drilling |
| 10/28/1997 | US5680902 Wellbore valve |
| 10/15/1997 | EP0690953B1 Drilling apparatus with drill string and percussion hammer drilling head |
| 10/09/1997 | WO1997037102A2 Downhole flow control devices |
| 10/07/1997 | US5673751 System for controlling the flow of fluid in an oil well |
| 10/02/1997 | DE19608815C1 Device for producing sealing floor in ground, used in construction |
| 09/25/1997 | WO1997035093A1 Method and apparatus using coiled-in-coiled tubing |
| 09/24/1997 | EP0796979A2 Floating apparatus for downhole use and method of making it |
| 09/20/1997 | CA2200415A1 A casing and method of installing the casing in a well |
| 09/18/1997 | WO1997034070A1 Device for drilling a bore hole in the ground |
| 09/18/1997 | DE19609899A1 Vorrichtung zur Herstellung eines Erdlochs Apparatus for producing a earthen hole |
| 09/17/1997 | EP0795074A1 Method and apparatus for drilling with high-pressure, reduced solid content liquid |
| 09/12/1997 | WO1997033071A1 Drill discharge apparatus |
| 09/10/1997 | EP0794317A2 Apparatus and method for injecting fluids in a well |
| 09/10/1997 | EP0793762A1 Pressure converter |
| 09/09/1997 | CA2188098A1 Control of particulate flowback in subterranean wells |
| 09/04/1997 | DE19607988A1 Coupling connecting rotary drilling drive to injector transferring mortar into rock anchor |
| 09/02/1997 | US5663121 Method and apparatus for providing a stream of inert gases in underbalanced drilling of a well bore |
| 09/02/1997 | US5662807 Apparatus and method for handling waste |
| 08/14/1997 | WO1997028906A1 Screen for vibrating separator |
| 08/13/1997 | EP0695333B1 Removing fines from a spent aqueous well treating fluid |
| 08/06/1997 | EP0787888A2 Circulating sub |
| 08/06/1997 | EP0787887A2 Portable liquid mud plant |
| 07/31/1997 | WO1997027381A1 Determination of fluid influx or efflux |
| 07/30/1997 | CN1155613A Method of nozzling while drilling with controllable negative pressure and apparatus thereof |
| 07/29/1997 | US5651420 For drilling a borehole in an earth formation |
| 07/15/1997 | US5648603 Method and apparatus for stabilizing a quantitative measurement gas trap used in a drilling operation |
| 07/15/1997 | US5647434 Floating apparatus for well casing |
| 07/08/1997 | US5646092 Pretreated clays, their preparation and use in formulation drilling muds not aggressive to layer clays |
| 07/08/1997 | US5645132 Drill bit having springless check valve and method of blocking backflow during drilling |
| 07/03/1997 | WO1997023707A1 Water separator for a down hole drill |
| 07/02/1997 | EP0781893A2 Apparatus and method for early evaluation and servicing of a well |
| 06/26/1997 | WO1997022677A1 Drilling fluid loss prevention and lubrication additive |
| 06/24/1997 | US5641070 Shale shaker |
| 06/24/1997 | US5641021 Well casing fill apparatus and method |
| 06/19/1997 | WO1997021900A1 Fluid drilling system |
| 06/18/1997 | EP0778915A1 Drill rod |
| 06/18/1997 | EP0778914A1 Drill casing installation equipment with external friction reducing means |
| 06/18/1997 | EP0583285B1 Use of selected oleophilic compounds with quaternary nitrogen to improve the oil wettability of finely divided clay and their use as viscosity promoters |
| 06/17/1997 | US5638904 Within wells |
| 06/12/1997 | WO1997021020A1 Down hole bypass valve |
| 06/11/1997 | EP0777813A1 Formation isolation and testing apparatus and method |
| 06/10/1997 | CA2010534C Wire line core drilling apparatus |
| 06/04/1997 | EP0776410A1 Method of and system for flushing boreholes |
| 06/03/1997 | US5634984 Contacting with solution containing two surfactants with different hydrophilic-lipophilic balance values and nonpolar diluent oil, rinsing with water |
| 06/03/1997 | US5634515 Geothermal heat-pump system and installation of same |
| 06/03/1997 | US5634485 Method and apparatus for retrofitting drilling rigs with a catch pan |
| 05/27/1997 | US5632604 Down hole pressure pump |
| 05/22/1997 | WO1997018382A1 Spear head assembly |
| 05/22/1997 | CA2236932A1 Spear head assembly |
| 05/21/1997 | EP0774564A2 Well casing fill apparatus and method |
| 05/21/1997 | EP0774563A2 Method and apparatus for navigational drilling |
| 05/21/1997 | EP0774040A1 Erosion resistant downhole mud diverter tool |
| 05/20/1997 | US5631313 Suspending medium for particulate material |
| 05/15/1997 | WO1997017522A1 Portable flare tank for degassing of drilling fluid |
| 05/13/1997 | US5628493 Oilfield valve |
| 05/09/1997 | WO1997016622A1 A drilling assembly, a coupling device for such drilling assembly, and a method of drilling holes in the underground using the drilling assembly |
| 05/06/1997 | US5626200 For use in a wellbore |
| 05/01/1997 | CA2188716A1 Downhole oil well tool running and pulling with hydraulic release using deformable ball valving member |
| 04/30/1997 | CN1148864A Rase oil for well-bore fluids |
| 04/29/1997 | US5624502 Storage wash water in vessel, cleaning the floating vessel, transmitting contaminated wash water, introducing coagulating cation polymer, settling, concentrating, decanting and separation |
| 04/24/1997 | WO1997014868A1 Purging means for purging upwards in ring spacing between drill pipe and bore hole wall |
| 04/24/1997 | WO1997014765A1 Method for extracting oil from oil-contaminated soil |
| 04/23/1997 | EP0682738B1 Drilling apparatus |
| 04/23/1997 | CN2252876Y Drilling tool for piling on rock |
| 04/08/1997 | US5618780 Lubricating composition including an ester-use of the composition and well fluid including the composition |
| 03/12/1997 | EP0760942A1 Apparatus for testing a shear thickening plugging fluid |
| 03/12/1997 | EP0760896A1 A well entry tool |
| 02/27/1997 | WO1996038653A3 Device for controlling the weight on an earth drill bit |
| 02/25/1997 | US5605192 Means and method to displace a logging tool to the bottom of a well for withdrawal through the well |
| 02/13/1997 | WO1997005361A1 Safeguarded method and apparatus for fluid communication using coiled tubing, with application to drill stem testing |
| 02/12/1997 | CN1142786A Solvent soaps and methods employing same |
| 02/06/1997 | WO1997004213A1 Hazardous waste characterizer and remediation method and system |
| 02/06/1997 | WO1997004182A1 Method of expanding a bore hole in ground containing hard material and a device for implementing the method |
| 02/05/1997 | CN2246705Y One way valve for fluid injection |
| 01/30/1997 | WO1997003274A1 Single trip whipstock assembly |
| 01/23/1997 | WO1997002405A1 Drilling apparatus |
| 01/23/1997 | WO1997002088A1 Improvements in or relating to ultrasonic processors |
| 01/23/1997 | WO1996034175A3 Cementing plug |
| 01/22/1997 | EP0754836A1 Method and apparatus for removing gelled drilling fluid and filter cake from the side of a well bore |