Baker Hughes Corporation

Hartmut Schrader

Thomas Kruspe

Holger Thern

Christian Kiesl

Frank Reiber

Martin Blanz

Robert Andrew Slade

Peter Rottengatter

Rob Hawkes

An expert system is included in a downhole processor designed to acquire and process NMR data downhole in real time. The downhole processor controls the acquisition of the NMR data based at least in part on instructions transmitted downhole from a surface location and at least in part on evaluation of downhole conditions by the expert system. The downhole conditions include drilling operation conditions (including motion sensors) as well as lithology and fluid content of the formation obtained from other MWD data. The wait time, number of echos, number of repetitions of an echo sequence, interecho time, bandwidth and shape of the tipping and refocusing pulses may be dynamically changed. Data processing is a combination of standard evaluation techniques. Selected data and diagnostics are transmitted uphole. The expert system may be implemented as a two stage neural net. The first stage does the formation evaluation and the second stage controls the NMR pulse sequence.

Downhole NMR processing

An NMR device is presented that includes a drill collar having non-rotating sleeve containing permanent magnets. The non-rotating sleeve is clamped against a borehole wall and decoupled from drilling vibrations during NMR measurements. The transmitter and receiver are located on the rotating part of the drill collar. Alternatively the permanent magnets and the RF receiver antenna and/or receiver electronics are placed on the non-rotating sleeve which is clamped against the borehole wall and decoupled from drilling vibrations, with the transmitting antenna located on the rotating drill collar. Alternatively a non-rotating stabilizer is provided above or below an NMR sensor. A stabilizer is activated to stabilize the rotating NMR sensor located on the drilling collar in the bore hole. The permanent magnets and receiving and transmitting antennas are located on a non-rotating sleeve that is clamped against the borehole wall to decouple the permanent magnets and receiving and transmitting antennas from drilling vibrations.

Method and apparatus for a downhole NMR MWD tool configuration

The present invention provides an apparatus and method for minimizing movement of a drill string during MWD with vibration-sensitive instruments comprising conveying a drill string into a borehole with a sensor mounted on the drill string for sensing a parameter of interest of a formation. A clocked controller is disposed on the drill string for controlling timing of the sensor; and a second clocked controller is disposed at a surface location. During drilling operations, the clocked controllers are synchronized such that the surface controller is performing certain tasks in timed sequence with the sensor even though the surface controller is not connected to the sensor.

Apparatus and method for synchronized formation measurement

A drilling fluid analyzing apparatus has at least two sensors is used to analyze drilling fluid that contains cuttings. The sensors are mounted vertically spaced in a well riser and in communication with well return fluid. The sensors convert the pressure exerted by the return fluid to signals that are then conveyed to a processor. The processor determines the density of the return fluid, and the fluid density is indicative of borehole cleaning efficiency. Two additional sensors may be added to the drilling fluid input mud pipe to sense the pressure exerted by the drilling mud before it is contaminated with cuttings.

Method and apparatus for measuring fluid density and determining hole cleaning problems

The present invention provides a fluid flow measurement system for an oil well drilling system that includes a supply of drilling fluid to a wellbore under pressure and a return line carrying fluid leaving the wellbore during drilling of the wellbore. The system includes at least one floating sensor in the return line that provides a measure of the velocity of the fluid in the return line. The sensor may be a thermal sensor, an electromagnetic sensor or an ultrasonic sensor. A height sensor provides the fluid level in the return line and a density sensor provides the density of the returning fluid. A controller determines the inflow rate and out flow rate of the drilling fluid and further determines the presence of a kick and wash out from the flow rates. The system also determines the operating condition of the pumps supplying fluid to the wellbore.

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Nienhagen, Germany

Hartmut Schrader