Halliburton Company

Billy W White

Michael J Lynch

Gilbert H Forehand

Richard L Duncan

Stephen E Tilghman

Ronald E Dant

Jack C Penn

Charles F VanBerg, Jr

Charles D Donaghe

J Mark Richardson

Terry O Anderson

John R Dennis

A self-contained downhole apparatus for being lowered into an oil or gas well to internally record samples of at least one environmental condition comprises three body sections linearly and releasably interconnected. One of the body sections is a selected one of a plurality of transducer housing sections. The selected transducer housing section is mechanically and electrically connected to a second body section containing microcomputer-operated signal processing circuitry. The third body section contains a power supply.

Self-contained downhole gauge system

A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and de-energizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations. Samples of the monitored environmental conditions can be taken at variable rates dependent upon software monitoring of the condition, the remaining battery life and the remaining memory capacity and in response to hardware monitored pressure changes. Each sample can be taken to a selectable resolution. A watchdog circuit monitors the microprocessor to insure that it is operating within a preselected time limit. Further, resolution counters (282) and (284), in association with multiplexer (280), provide selectable timing signals.

Self-containing downhole gauge system

In an oil well instrumentation system, the downhole sensor system is controlled by a computer which is powered-on only during sampling movement. An independent circuit, continuously powered, detects significant sensor rate-of-change values whereby the computer-sampling equipment is powered-on. A self-contained memory gauge includes either semiconductor or magnetic core memory for retaining downhole information related to sampled parameters, such as borehole temperature and pressure. A microprocessor-based computer manages the power utilization by independently and selectably energizing and deenergizing different sections of the gauge. The magnetic core memory is tested for operability, and the addressing of the magnetic core memory is adjusted in accordance with any inoperable memory locations. Samples of the monitored environmental conditions can be taken at variable rates dependent upon software monitoring of the condition, the remaining battery life and the remaining memory capacity and in response to hardware monitored pressure changes. Each sample can be taken to a selectable resolution. A watchdog circuit monitors the microprocessor to insure that it is operating within a preselected time limit.

A housing which is connectible to a pressure sensitive tool has a filter cartridge mounted within it to communicate a pressure from an external fluid to a clean fluid contained within the filter cartridge and the tool. The filter cartridge includes one or more filters having a plurality of passageways small enough to hold the clean fluid under pressure equilibrium conditions, but large enough to communicate pressure from the external fluid to the clean fluid. There are enough of such passageways so that it is unlikely that all will become clogged by any contaminants within the external fluid should a portion of the external fluid be sucked in through the filter in response to expansion and contraction phenomena of the clean fluid.

Pressure communicating, fluid isolating interface

A housing which is connectible to a pressure sensitive tool has a filter cartridge mounted within it to communicate a pressure from an external fluid to a clean fluid contained within the filter cartridge and the tool. The filter cartridge includes one or more filters having a plurality of passageways small enough to hold the clean fluid under pressure equilibrium conditions, but large enough to communicate pressure from the external fluid to the clean fluid. There are enough of such passageways so that it is unlikely that all will become clogged by an contaminants within the external fluid should a portion of the external fluid be sucked in through the filter in response to expansion and contraction phenomena of the clean fluid.

The method for controlling the rate at which a downhole logging tool samples and records a detected condition obtains three samples of the condition at three consecutive sample times and computes a prediction value for the n-th sample from the first three samples. The method compares the actual n-th sample with the predicted value and records the (n- 1)-th sample if the variance between the predicted and actual values is outside a predetermined threshold or difference. The sample rate is changed if the actual values of the samples remain within the predicted value's preselected range for more than a preselected number of samples. The sample rate interval is also increased if the battery life or memory capacity decrease below predetermined thresholds. The sample rate interval is decreased to its shortest interval if a pressure change above a predetermined threshold is detected.

Method of sampling environmental conditions with a self-contained

The cable head provides an H.sub.2 S resistant assembly which includes a weak link therein substantially isolated from any stress other than tensile stress induced by the logging cable. The cable head also provides a fishing neck at the top of the tool string after the weak link is severed and the wireline retrieved. Moreover, the logging cable is positively secured to the cable head by a force-fit wedge, and the design thereof ensures that parting of the weak link also provides for a positive mechanical disengagement of the logging cable from the cable head. Finally, an external sinker bar has been provided which mounts externally of the cable head, surrounding the logging cable above the cable head and mechanically interlocking therewith; such sinker bars may be run above the cable head in series, each interlocking with the one below it.

Sour gas cable head

The present invention comprises an exoskeletal packaging arrangement for electronic circuitry and components employed in downhole tools such as are deployed in the bores of oil and gas wells. The invention includes a monocoque structure comprising interlocked bulkheads and shell plates, within which the electronic circuitry and components are protected in substantial isolation from vibration and shock. Also included in the invention is a coupling for providing an environmentally sealed electrical connection between adjacent tool housings containing the aforesaid bulkhead/shell plate monocoque structure.

Exoskeletal packaging scheme for circuit boards

The present invention comprises a quick change coupling for hostile environment including means to assure alignment of electrical connectors carried by mating male and female components of said coupling, seal means between said components, and biasing means to assure the continued, non-damaging engagement of said electrical connectors.

Growing community of inventors

Duncan, OK, United States of America

Billy W White