Measuring and testing – Borehole or drilling – Formation logging
Reexamination Certificate
1998-02-27
2001-05-29
Williams, Hezron (Department: 2856)
Measuring and testing
Borehole or drilling
Formation logging
C073S152460, C073S152540, C175S050000, C175S040000
Reexamination Certificate
active
06237404
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to an apparatus and method for measuring properties of an earth formation traversed by a borehole, and more particularly, to an apparatus and method for determining a drilling mode to optimize formation evaluation measurements.
To make downhole measurements while a borehole is being drilled, measurement-while-drilling (MWD) and/or logging-while-drilling (LWD) systems are generally known which measure various useful parameters and characteristics such as the formation resistivity and the natural gamma ray emissions from the formations. Signals which are representative of these measurements made downhole are relayed to the surface with a mud pulse telemetry device that controls the mud flow, encoding information in pressure pulses inside the drill string. The pulses travel upward through the mud to the surface where they are detected and decoded so that the downhole measurements are available for observation and interpretation at the surface substantially in real time. As an alternative, it has also been found useful to provide a downhole computer with sufficient memory for temporarily storing these measurements until such time that the drill string is removed from the borehole.
U.S. Pat. Nos. 5,130,950 issued to Orban et al., 5,241,273 issued to Martin Lüling, 5,017,778 issued to Peter D. Wraight, 5,148,407 issued to Haldorsen et al., 5,585,556 issued to Petersen et al., and 5,705,927 issued to Sezginer et al., describe MWD tools which employ nuclear magnetic resonance, sonic, seismic, nuclear, or electromagnetic measurements. The tools disclosed in the prior art have disadvantages which limit their utility in MWD and/or LWD applications. Sonic, resistivity, nuclear, electromagnetic, and seismic measurements are directly influenced by the drilling noise. For example, while acoustic energy generated at the surface is usually very large, the energy that must be detected at the drill bit can be very small due to geometrical spreading and attenuation of the acoustic waves in the subsurface formation. In many cases, the drilling noise is orders of magnitude larger than the acoustic wave energy propagating from the surface to the subsurface MWD detector. Also, MWD and LWD nuclear magnetic resonance measurements are directly influenced by the vertical and lateral motion of the tool. For example, due to the amount of time required to obtain T
1
and T
2
measurements, the formation properties may change during the measurement cycle. These aforementioned factors adversely affect MWD and/or LWD measurements.
In the presence of a noisy drilling environment, the prior art tools obtain nuclear magnetic resonance, sonic, electromagnetic, nuclear, and seismic measurements directly influenced by the vertical and lateral tool motion and the drilling noise. None of the MWD and/or LWD tools determine the drilling mode and accordingly modify the data acquisition sequence to optimize formation evaluation measurements.
SUMMARY OF THE INVENTION
The above disadvantages of the prior art are overcome by means of the subject invention for an apparatus and method for determining a drilling mode to optimize formation evaluation measurements. A drill string, which includes an MWD tool, an LWD tool, or a plurality of tools, drills a borehole into the formation. Standard rotary drilling operations contain many natural pauses where the tool remains stationary: connection time as a new section of drill pipe is added to the drill string, circulation time when mud is circulated and the drill pipe is possibly rotated, and fishing or jarring time while the drill string is stuck and has to be freed before drilling can resume. These natural pauses, which occur without interrupting normal drilling operations, are utilized to make formation evaluation measurements of the subsurface formation that take a long time or that benefit from a quiet environment, such as nuclear magnetic resonance, seismic, sonic, nuclear, or electromagnetic measurements. A deliberate pause can be initiated, causing a portion of the drill string to remain stationary.
In order to utilize the pause interval to optimize formation evaluation measurements, the subject invention detects downhole conditions, determines the drilling process mode of operation, and modifies the data acquisition sequence. The detected downhole conditions include mud flow, acceleration of the drill string, bending of the drill string, weight-on-bit, and rotation of the drill string. The drilling process modes include drilling, sliding, tripping, circulating, fishing, a short trip (up or down), and drill pipe connections.
REFERENCES:
patent: 2677790 (1954-05-01), Arps
patent: 2973471 (1961-02-01), Armistead et al.
patent: 3115774 (1963-12-01), Kolb
patent: 3237093 (1966-02-01), Bennett et al.
patent: 3865201 (1975-02-01), Haden
patent: 4223399 (1980-09-01), Hackett
patent: 4474250 (1984-10-01), Dardick
patent: 4549431 (1985-10-01), Soeiinah
patent: 4763258 (1988-08-01), Engelder
patent: 5017778 (1991-05-01), Wraight
patent: 5130950 (1992-07-01), Orban et al.
patent: 5148407 (1992-09-01), Haldorsen et al.
patent: 5241273 (1993-08-01), Luling
patent: 5349337 (1994-09-01), McCormick
patent: 5448227 (1995-09-01), Orban et al.
patent: 5467832 (1995-11-01), Orban et al.
patent: 5581024 (1996-12-01), Meyer, Jr. et al.
patent: 5585556 (1996-12-01), Petersen et al.
patent: 5705927 (1998-01-01), Sezginer et al.
patent: 5774420 (1998-06-01), Heysse et al.
patent: 5842149 (1998-11-01), Harrell et al.
patent: 6021377 (2000-02-01), Dusinsky et al.
Crary Steven F.
Esmersoy Cengiz
Heidler Ralf
Poitzsch Martin E.
Jeffery Brigitte L.
Ryberg John J.
Schlumberger Technology Corporation
Wiggins David J.
Williams Hezron
LandOfFree
Apparatus and method for determining a drilling mode to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for determining a drilling mode to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for determining a drilling mode to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2507249