Drill‐bit seismic monitoring while drilling by downhole wired‐pipe telemetry

Abstract

Drill‐bit seismic while drilling provides reverse vertical seismic profiles with large configurations of surface seismic sensors. This seismic while drilling technique makes it possible to predict the formation changes ahead of the bit and to image 2D and 3D structures without interfering with the drilling activity. The method is based on the recording of reference (pilot) signals which enable us to recognize and process the signal of the downhole drill‐bit source, thus obtaining impulsive seismograms after the crosscorrelation and deconvolution of the pilot signals and the seismic data recorded by surface or crosswell geophones. One issue in the application of this methodology can be the loss of the transmitted energy for the reference signal propagated from the bit to the surface through the drill string, when the pilot signals are recorded at the surface, at the top of the drill string. It is well known that with polycrystalline diamond compact bits, the pilot signal recorded at the surface may be weak and consequently the seismic while drilling results are poor. This may also happen during drilling in the sliding mode without pipe rotation, and in highly deviated or horizontal wells. A solution to improve the drill‐bit seismic while drilling method in these conditions is to record the reference signal in the proximity of the bit source, using downhole near‐bit tools to get good‐quality measurements of the pilot signal. We present drill‐bit seismic while drilling results obtained in a drilling test using wired pipes for high‐rate communication from bottom hole to the surface. The results demonstrate the applicability of this integrated approach as a standard procedure. The advantage of this is to provide real‐time synchronized reverse vertical seismic profiles, as well as high‐resolution and good‐quality data in terms of S/N and high‐frequency content. The method improves the use of the working drill bit as a downhole seismic source with different types of bit and drilling conditions.

Circuit Modeling and Signal Transmission Analysis of Inductive Coupler in Wired Drill Pipe

“…A higher transmission rate of downhole information of MWD/LWD can make the drill bit travel along a predetermined track in real time to achieve safe drilling [2]. e telemetry drill string system [3,4] uses a high-frequency electromagnetic signal to realize the high-speed wired transmission of downhole information, and the transmission rate can reach 2 Mbit/s, which is much higher than the conventional wireless transmission technology of downhole information such as mud pressure pulse [5], formation electromagnetic wave [6], and drill string acoustic wave [7,8], indicating good potential for practical application. e system is composed of a series of wired drill pipes.…”

Research Note: Automated data‐driven alignment of near‐bit and top‐drive vibration sensors for seismic while drilling and beyond

“…As a result, the clock errors tend to be large and require a significant correction. Fast telemetry, such as wired drill pipe technology (Naville et al ., 2004; Poletto et al ., 2014), may offer real‐time data transmission and an alternative solution to solve the time‐alignment issue using existing tools; however, it has received limited penetration in the industry thus far. This study aims to solve this problem for conventional memory‐based near‐bit sensors with inexpensive unsynchronized clocks experiencing significant and temperature‐dependent drift.…”

Retrieving virtual reflection responses at drill‐bit positions using seismic interferometry with drill‐bit noise

“…Most methods in SWD rely on pilot signals (estimates of the seismic signature of the drill bit) to compress the drill-bit signal to an impulse (Rector and Marion 1991;Poletto, Rocca, and Bertelli 2000;Poletto et al 2014). Standard SWD processing involves cross-correlation of pilot signals and geophone recordings, reference deconvolution, and pilot-delay shift.…”

“…Besides passive noise, active noise with known locations, such as drill-bit noise, has long been used in seismicwhile-drilling (SWD) to obtain reverse vertical seismic profiles (Rector and Marion 1991; and to provide look-ahead information while drilling (Malusa, Poletto, and Miranda 2002;Eidsvik and Hokstad 2006). Most methods in SWD rely on pilot signals (estimates of the seismic signature of the drill bit) to compress the drill-bit signal to an impulse (Rector and Marion 1991;Poletto, Rocca, and Bertelli 2000;Poletto et al 2014). Standard SWD processing involves cross-correlation of pilot signals and geophone recordings, reference deconvolution, and pilot-delay shift.…”