Nabors Drilling Technologies Usa, Inc.

Stephen Krase

Peter R Harvey

Christopher Viens

Peter Harvey

A control system that corrects differential pressure measurements with downhole annulus pressure information is disclosed. When differential pressure is zeroed with the BHA off-bottom, the annulus pressure value is baselined. During drilling, a controller receives surface differential pressure measurements and annulus pressure measurements. As the controller receives each new annulus pressure measurement, it compares it to the baseline annulus pressure value to obtain a different annulus pressure value. The controller corrects the surface differential pressure measurements with the annulus pressure measurements. As the controller receives each new surface differential pressure measurement, it subtracts out the current difference annulus pressure value. As a result, the modified surface differential pressure measurement remains a reflection of mud motor performance that removes the influence of the increased density of the fluid, thereby improving autodrilling control. The modified surface differential pressure measurements are also used to determine mud motor torque.

Autodrilling control with annulus pressure modification of differential pressure

An improved MWD system for drilling unconventional wells. Embodiments provide a particular combination of sensors in a specific arrangement in order to provide a system expressly designed for drilling unconventional wells. By minimizing modularity to reduce the need for redundant/duplicated components, including only sensors specifically needed for unconventional wells, and by separating long-life components such as sensors from components requiring more frequent maintenance or service such as batteries, the components can be more efficiently combined into a BHA sensor assembly having the shortest possible length.

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Spring, TX, United States of America

Stephen Krase