11
Le Foll Pierre: Underbalance drilling downhole choke. Schlumberger Services Petrol, January 2, 2004: EP1375817-A1 (30 worldwide citation)

A method for underbalance drilling in a reservoir comprises operating a variable aperture of a downhole choke located at a downhole extremity of a drill string. The variable aperture allows to control a pressure differential between a drilling fluid pumped down the drill string from surface and flow ...


12
Ciglenec Reinhart, Tabanou Jacques R, Hutin Remi: Formation data sensing with deployed remote sensors during well drilling. Anadrill Int, Schlumberger Services Petrol, December 9, 1998: EP0882871-A2 (30 worldwide citation)

A method and apparatus for acquiring data representing formation parameters while drilling a wellbore is disclosed. A well is drilled with a drill string having a drill collar that is located above a drill bit. The drill collar includes a sonde section having transmitter/receiver electronics for tra ...


13
Clark Brian, Hunka John, Frey Mark T, Smith David L, Ramaswamy Dhananjay, Collins Anthony L, Bonner Stephan D: Downhole signal communication and measurement through a metal tubular. Schlumberger Services Petrol, Schlumberger Technology, Schlumberger Holdings, November 28, 2001: EP1158138-A2 (27 worldwide citation)

Systems and methods for downhole communication and measurement utilizing an improved metallic tubular (30) having an elongated body with tubular walls and a central bore (32) adapted to receive a run-in tool (10). The tubular including slotted stations to provide through-tubular signal transmission ...


14
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 ...


15
Ciglenec Reinhart, Tabanou Jacques R: Formation pressure measurement with remote sensors in cased boreholes. Schlumberger Holdings, Schlumberger Services Petrol, March 8, 2000: EP0984135-A2 (27 worldwide citation)

A method and apparatus are disclosed for establishing communication in a cased wellbore with a data sensor (16) that has been remotely deployed, prior to the installation of casing in the wellbore, into a subsurface formation (20) penetrated by the wellbore. Communication is established by installin ...


16
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 ...


17
Danican Samuel, Ding Beilin, Drochon Bruno, James Simon: Permeable cements. Schlumberger Services Petrol, Schlumberger Technology, Schlumberger Holdings, Sofitech, November 27, 2002: EP1260491-A1 (23 worldwide citation)

A permeable cement composition comprises an aqueous slurry of a hydraulic cement including a water-immiscible dispersed fluid phase, such as oil or gas, and a hollow particulate material, the hollow particulate material being one which breaks down in the presence of the cement so as to leave voids w ...


18
Rayssiguier Christophe, Allouche Mickael: Method and apparatus to set a plug in a wellbore. Schlumberger Services Petrol, Schlumberger Technology, Schlumberger Holdings, Prad Res & Dev, February 28, 2007: EP1757770-A1 (22 worldwide citation)

The invention provides an apparatus to be lowered in a borehole, comprising: (i) a delivery section for delivering a plugging fluid; (ii) a setting section comprising a longitudinal element and a flexible sleeve into which the plugging fluid is delivered; and (iii) a disconnect mechanism to allow th ...


19
Thambynayagam Raj Kumar Michae, Tilke Peter G, Bryant Ian D, Auzerais Francois M, Bennett Nicholas N, Ramakrishnan T S: Oilfield analysis systems and methods. Schlumberger, Schlumberger Technology, Schlumberger Services Petrol, Schlumberger Holdings, August 14, 2002: EP1230566-A1 (22 worldwide citation)

An oilfield data analysis system is based on a four-tier software model which includes a "shared earth model" and a federation of "directory services". The first tier is a universal graphical user interface (GUI) which can operate on any inexpensive computer (12) as well as on an expensive workstati ...


20
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 ...