While-drilling apparatus for measuring streaming potentials and determining earth formation characteristics and other useful information
First Claim
1. An apparatus for investigating an earth formation traversed by a borehole, the apparatus comprising:
- a) a drill string terminated by a drill bit;
b) a plurality of electrodes that are adapted to measure streaming potential voltage signals, wherein at least one of said plurality of electrodes is defined by said drill bit; and
c) at least one of first circuitry which derives a DC component of a given streaming potential voltage signal and second circuitry which derives an AC component of a given streaming potential voltage signal.
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Accused Products
Abstract
Logging-while-drilling apparatus and methodologies for measuring streaming potential in an earth formation are provided. The apparatus and methodologies can be utilized to find information relevant to the drilling operations. In particular, since the streaming potential measurement relates directly to fluid flow, the streaming potential measurements can be used to track flow of fluids in the formation. In turn, this information may be used to find information relevant to the drilling operations, such as under-balanced drilling conditions, abnormal formation pressures, open fractures, the permeability of the formation, and formation pressure.
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Citations
22 Claims
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1. An apparatus for investigating an earth formation traversed by a borehole, the apparatus comprising:
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a) a drill string terminated by a drill bit; b) a plurality of electrodes that are adapted to measure streaming potential voltage signals, wherein at least one of said plurality of electrodes is defined by said drill bit; and c) at least one of first circuitry which derives a DC component of a given streaming potential voltage signal and second circuitry which derives an AC component of a given streaming potential voltage signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification