21
Daniel Codazzi: Kick detection during drilling. Anadrill, Gary L Bush, John J Ryberg, October 13, 1992: US05154078 (29 worldwide citation)

Gas influx into a wellbore, called A "kick", is detected by two different, yet complementary methods during active drilling of the borehole. The first method is based upon the existence of standing wave patterns generated by pressure oscillations of the drilling rig mud pumps. Such standing wave pat ...


22
Warren E Askew: Hydraulic drilling jar. Anadrill, David L Mosely, John J Ryberg, July 23, 1991: US05033557 (28 worldwide citation)

In accordance with an illustrative embodiment of the present invention, a hydraulic drilling jar includes a mandrel and a housing movable between extended and retracted relative positions to deliver jarring blows to a struck object, a piston on the mandrel that slides in a cylinder in the housing, a ...


23
Mark Coles: Method to improve directional survey accuracy. Anadrill, Stephen L Borst, John J Ryberg, September 18, 1990: US04956921 (28 worldwide citation)

A method is proposed for better determining the azimuth and inclination of a borehole in which a priori information regarding the magnitude of the earth's gravitational field strength, its magnetic field strength and direction are utilized to constrain the measured components of the earth's gravitat ...


24
Michael Sheppard, Zhian Hedayati: Method for improving a drilling process by characterizing the hydraulics of the drilling system. Anadrill, John J Ryberg, Stephen L Borst, July 17, 1990: US04941951 (27 worldwide citation)

A variety of flow and pressure measurements are obtained to characterize the drilling fluids hydraulics system of the borehole drilling process. Notably, a differential pressure measurement which measures the difference between the pressure internal to and external of the drill bit is made close to ...


25
Hall David: High performance bearing pad for thrust bearing.. Anadrill Int, Schlumberger Services Petrol, May 26, 1993: EP0543461-A2 (27 worldwide citation)

Cylindrical bearing pads are insertable into bearing pad recesses formed in a receiving surface of a bearing pad retainer in a load-carrying structure. The bearing pads have an insertion end which is fixed into the bearing pad recess by brazing or by interference fitting and a bearing end which proj ...


26
Ohmer Herve: Method and apparatus for establishing branch wells at a node of a parent well. Anadrill Int, Schlumberger Services Petrol, September 17, 1997: EP0795679-A2 (24 worldwide citation)

A method and apparatus for creating multiple branch wells from a parent well is disclosed. A multiple branching sub is provided for placement at a branching node of a well. Such sub includes a branching chamber and a plurality of branching outlet members. The outlet members during construction of th ...


27
Christopher G Casso: System and method for monitoring drill bit depth. Anadrill, John J Ryberg, David P Gordon, December 11, 1990: US04976143 (22 worldwide citation)

Methods and apparatus for accurately determining drill bit depth are provided. A hook load is sampled at a rate of at least 4 Hz and is compared to a low threshold to establish a slips-in condition. A determination is made retroactively that the drill string stopped moving when the hook load passed ...


28
Aron Jeffrey B, Chang Shu Kong, Klasel Donald A, Lau Ting M: Transducer for sonic logging-while-drilling. Anadrill Int, Schlumberger Services Petrol, June 11, 1997: EP0778473-A2 (21 worldwide citation)

An acoustic wave transducer useful in sonic logging while drilling a borehole includes an array of transducer elements mounted circumferentially around a drill collar. The elements are bonded in an elastomer ring that is received in an external groove in the collar and are protected by a shield havi ...


29
Prevedel Bernhard, Askew Warren, Eddison Alan: Directional drilling methods and apparatus.. Anadrill Int, Schlumberger Services Petrol, August 5, 1992: EP0497420-A1 (21 worldwide citation)

In accordance with illustrative embodiments of the present invention, more accurate directional drilling is carried out by providing a downhole adjustable bent housing that is selectively operated to produce a bend angle in the drill string between a downhole motor and the drill bit, providing a nea ...


30
Orban Jacques, Richardson Neil W: Method of and apparatus for making near-bit measurements while drilling.. Anadrill Int, Schlumberger Services Petrol, August 4, 1993: EP0553908-A2 (21 worldwide citation)

In accordance with illustrative embodiments of the present invention, a measuring-while-drilling system includes a sensor sub (22) positioned at the lower end of a downhole motor assembly (14) so that the sub is located near the drill bit (13). The sub houses instrumentalities that measure various d ...