Schlumberger Technology Corporation

Multi-shot LLC

Schlumberger Canada Limited

Garry Holmen

Derek W Logan

Aaron William Logan

Brian Oliver Clark

Reza Taherian

Anthony Robert Dopf

Tony Dopf

Rob Utter

Kjell Haugvaldstad

Robert J Utter

Jeff Payne

Keith Runnels

A gap sub assembly and methods for using the gap sub provide an electrical isolating joint that is mechanically strong enough to withstand the rigors of drilling environments, resistant to environmental effects (heat, corrosive liquids and gases, and high pressures), and maintainable. The gap sub assembly provides a male member and a female member that may be connected together, wherein a non-conductive material is applied between the two at the attachment points. A locking ring or collar affixes to both male and female members to prevent back off while drilling and preserving the electrical isolation of the gap joint. Non-conductive material may be injected between the locking ring and one or more of the male or female members.

System and method for manufacturing electrically isolated connection for electromagnetic gap sub assembly

This invention provides an improved system and method for receiving electromagnetic (EM) signals from a wellbore in spite of EM unfriendly formations by placing a cable antenna in a wellbore, drilling another wellbore nearby, and using the cable antenna downhole in the wellbore to assist in receiving signal from the transmitter in the wellbore being drilled. The EM telemetry system can include a bottom hole assembly with an EM tool for transmitting a signal positioned in a first wellbore; EM equipment provided at or near the surface; and a cable antenna coupled to the EM analyzer positioned in a second wellbore. The cable antenna does not require other downhole antenna devices for receiving EM signals and therefore is independent of other antenna devices. The cable antenna can be retrieved after drilling is completed and moved to another drilling site.

Retrievable downhole cable antenna for an electromagnetic system

A drill bit assembly having an electrically isolated gap joint for electromagnetic telemetry comprises a drill bit, a pin body, an electrically insulating gap joint therebetween, and an electrical conductor extending across the gap joint. The bit head has a cutting end and an opposite connecting end with an engagement section. The pin body has a tubular body with an axial bore therethrough, and comprises a connecting end with an engagement section. The pin body connecting end is connected to the bit head connecting end such that the engagement sections overlap. The electrically insulating gap joint fills an annular gap between the bit head and pin body engagement sections such that the bit head and pin body are mechanically connected together at the connecting ends but are electrically separated. The electrical conductor has one end electrically contacting one of the bit head and pin body, and the other end communicable with electronics equipment.

Drill bit assembly having electrically isolated gap joint for electromagnetic telemetry

A drill bit assembly for measuring reservoir formation properties comprises a bit head and a pin body, and an electrically insulated gap joint between two conductive parts of the drill bit assembly. The bit head has a cutting end and an opposite connecting end with an engagement section. The pin body comprises a connecting end with an engagement section. The pin connecting end is connected to the bit head connecting end such that the engagement sections overlap. The electrically insulating gap joint can fill a gap between the bit head and pin body engagement sections such that the bit head and pin body are mechanically connected together at the connecting ends but electrically separated. Alternatively or additionally, the pin body can have two pieces which are separated by an electrically insulating gap joint. An electrical conductor is electrically connected at a first end to the bit head and is communicable at a second end with an alternating current signal to transmit an alternating current into the bit head, thereby inducing an electric current into a reservoir formation adjacent the bit head. Electronic equipment includes measurement circuitry configured to determine the alternating current at the bit head, the alternating current being inversely proportional to a bit resistivity of the formation.

Drill bit assembly having electrically isolated gap joint for measurement of reservoir properties

A drill bit assembly has a bit head and a pin body. The bit head comprises a cutting end, an opposite connecting end with an engagement section, and a feature facing the connecting end. The pin body comprises a tubular body with an axial bore therethrough, a connecting end with an engagement section and a feature facing the connecting end. The drill bit assembly is manufactured by positioning the pin body connecting end with the bit head connecting end such that the pin body and bit head engagement sections overlap with a gap therebetween, and the pin body and bit head features are aligned; injecting a thermoplastic or other connecting material in liquid form between the bit head and pin body engagement sections and into the gap; and solidifying the thermoplastic or other connecting material such that the bit head and pin body are mechanically coupled together at their connecting ends and their features are securely aligned.

Drill bit assembly having aligned features

Oilfield drilling utilizes downhole data transmitted to surface for formation evaluation and steering of directional wellbores. A leading technology in providing subsurface to surface communication is Electro-Magnetic (EM) Telemetry. This technology is typically employed with a downhole antenna concentric with the bore of an electrically insulating 'gap sub' portion of the system. The antenna blocks the bore from further use to conduct other sensors or equipment through. One aspect of the invention is to integrate the antenna into the structure of the gap sub, thereby clearing the bore for conducting other tools through, and also protecting the antenna from the harsh drilling environment, including abrasion, erosion, shock, and vibration. Another aspect of this invention enables the antenna to serve a secondary function as an anti-rotation feature between the two halves of the gap sub.

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Calgary, Canada

Garry Holmen