Method for borehole measurement of formation properties
OwnerHans Thomann, Charles Fred Pepper +1inventors
InventorsHans Thomann, Charles Fred Pepper, Stuart Ronald Keller
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Abstract
The present invention is a method of estimating formation properties by analyzing acoustic waves that are emitted from and received by a bottom hole assembly.
Claims22
A method of using a bottom hole assembly deployed in a borehole to estimate a formation property comprising the steps of:
- (a) generating a source signal from said bottom hole assembly;
- (b) detecting at least one receiver signal using said bottom hole assembly;
- (c) computing a frequency dependent characteristic of said at least one receiver signal;
- and
- (d) using said frequency dependent characteristic to estimate said formation property.
The method of claim 2 wherein said tool is a bottom hole assembly of a drilling apparatus.
A method of continuously estimating the pore pressures of formations ahead of a bottom hole assembly, comprising the steps of
- a) generating a source signal from said bottom hole assembly;
- b) detecting at least one receiver signal using said bottom hole assembly;
- c) using said source signal and said receiver signal to estimate a pore pressure of at least one said formation;
- and
- d) repeating steps a), b), and c) as said bottom hole assembly moves sequentially downward through said formations.
A method of continuously monitoring the wellbore pressure safety margin corresponding to formations ahead of a bottom hole assembly, comprising the steps of
- a) generating a source signal from said bottom hole assembly;
- b) detecting at least one receiver signal using said bottom hole assembly;
- c) using said source signal and said receiver signal to determine a pore pressure of said formation;
- d) using said pore pressure to monitor said wellbore pressure safety margin;
- and
- e) repeating steps a), b), c) and d) as said bottom hole assembly moves sequentially downward through said formations.
A method of continuously optimizing the weight of drilling mud used in a drilling operation, comprising the steps of
- a) generating a source signal from a bottom hole assembly;
- b) detecting at least one receiver signal using said bottom hole assembly;
- c) using said source signal and said receiver signal to determine a pore pressure of a formation ahead of said bottom hole assembly;
- and
- d) using said pore pressure to specify a weight of said drilling mud which corresponds to a target wellbore pressure safety margin.
Dependencies are inferred from the claim text.