Engineering Aspects of LWD Quadrupole Measurements and Field Test Results (2003)

Engineering Aspects of LWD Quadrupole Measurements and Field Test Results V. Dubinsky; V. Dubinsky Houston Technology Center, Baker Atlas / INTEQ, USA Search for other works by this author on: This Site Google Scholar X.M. Tang; X.M. Tang Houston Technology Center, Baker Atlas / INTEQ, USA Search for other works by this author on: This Site Google Scholar A. Bolshakov; A. Bolshakov Houston Technology Center, Baker Atlas / INTEQ, USA Search for other works by this author on: This Site Google Scholar D. Patterson D. Patterson Houston Technology Center, Baker Atlas / INTEQ, USA Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. Paper Number: SPE-84248-MS https://doi.org/10.2118/84248-MS Published: October 05 2003 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Dubinsky, V., Tang, X.M., Bolshakov, A., and D. Patterson. "Engineering Aspects of LWD Quadrupole Measurements and Field Test Results." Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. doi: https://doi.org/10.2118/84248-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractThis paper presents the principle and engineering aspects of an LWD quadrupole shear wave tool. Extensive theoretical study and a series of laboratory and field experiments have been conducted to verify that the quadrupole measurements can determine the true shear velocity of the formation. Experimental results based on the actual laboratory and downhole while drilling measurements are presented in this paper. A multipole (i.e., monopole, dipole, and quadrupole) LWD acoustic tool has been constructed. This tool allows downhole recording of raw and stacked signals acquired by individual receiver elements of the tool. This tool consists of a universal source, which can operate at different frequencies in all three modes, i.e., monopole, dipole, and quadrupole. The six-station receiver array, with four individual receiver elements per station, permits signal acquisition in all these modes. In addition, a triaxial accelerometer system is used to monitor drilling dynamics while drilling.By making multiple snapshots of the signals in different modes downhole for various drilling conditions, we demonstrate that, when operating in the quadrupole mode, the acoustic signals acquired by the LWD tool possess the true quadrupole characteristics. Comparison of the dipole, monopole, and quadrupole signatures clearly demonstrates how common mode noise is efficiently suppressed in the quadrupole mode. The result shows that even in the case of severe lateral vibrations the combined quadrupole signal provides satisfactory shear wave measurements. The data processing/analysis results are presented. Field-measured quadrupole LWD shear data are evaluated for different drilling scenarios.IntroductionOne of the main challenges in LWD acoustics is the ability to measure shear-wave velocity reliably and accurately in the drilling environment. Tool mode contamination/modification of the LWD acoustic waves and the presence of significant drilling noise present a serious obstacle to the shear-wave velocity measurement. To address these issues, a quadrupole-wave technology has recently been utilized for the measurement. An advantage of the technology is the quadrupole contaminating tool mode does not exist at a lower frequency. Furthermore, the low frequency, quadrupole wave velocity is the formation's shear velocity.Many of the LWD acoustic measurements and principles are related to wireline acoustic logging, already a mature technology. Both compressional and shear velocities of the formation can be reliably and accurately measured for a variety of formations using a wireline tool. Over the past several decades, the industry has accumulated ample knowledge in this field. Advanced wireline technologies, such as cross-dipole measurements, allow evaluation of azimuthal anisotropy, which can be utilized for determination of the principal stress direction and other important characteristics of the rock.The success of wireline acoustic technology sets a benchmark for the expected quality and comprehensiveness of the LWD acoustic measurements in various environments. As a result, oil and gas production companies naturally have extended these expectations to the LWD acoustic services. Although LWD acoustics is still an immature technology, it has been developing rapidly for the last several years. The requirements for the LWD measurement pose serious challenges for the near future development. Although the real-time LWD compressional measurement has now become a reality1,2,3, the LWD shear measurements have only recently been introduced to the industry. At present, these measurements can still be qualified as pseudo real-time measurements because they require human interaction in the post-processing of the data recorded and stored in the LWD acoustic tool memory4,5,6. Keywords: well logging, quadrupole measurement, slowness, drilling noise, log analysis, receiver station, whirl, noise, modeling, acoustic source Subjects: Formation Evaluation & Management, Open hole/cased hole log analysis This content is only available via PDF. 2003. Society of Petroleum Engineers You can access this article if you purchase or spend a download.