Method for borehole measurement of formation properties
First Claim
1. 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.
0 Assignments
0 Petitions
Accused Products
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. A bottom hole assembly may be deployed in a borehole to estimate formation properties. From the bottom hole assembly, a source signal may be emitted and at least one signal may be received by one or more receivers in the bottom hole assembly. Analysis of the frequency dependent characteristics of the received signal allows the estimation of the formation properties of interest, including pore pressure. The formation properties of interest may be used to monitor a wellbore pressure safety margin and to optimize drilling mud weight.
-
Citations
24 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 23, 24)
-
-
20. 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 wherein said source signal is a noise spectrum generated by a drill bit; 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.
-
-
21. 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 wherein said source signal is a noise spectrum generated by a drill bit; 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.
-
-
22. 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 wherein said source signal is a noise spectrum generated by a drill bit; 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.
-
Specification