Numerical Calculation on Directional Radiation Technique to Near-Borehole Formation Through Casing
详细信息
- 责任者：Chen Xuelian (College of Geo-Resources and Information ; China University of Petroleum ; Dongying 257061 ; China) ; Wu Jinping
- 刊名：Journal of China University of Petroleum
- 出版年：2010
- 卷期：34(3)
- 关键词：声波测井 ; acoustical logging ; 套管内测井 ; logging through casing
- 页码：p.43-47,52
- 图表：8 illus., 1 table, 11 refs.
- 分类号：1600
- issnNo：ISSN1673-5005
- isbnNo：CN37-1441/TE
摘要
Aimed at the engineering requirements of measuring formation structure through casing, the acoustic fields of near-borehole formation excited by the linear phased-array source(LPAS) in cased boreholes with different bonding conditions were simulated using the real axis integration method. The numerical results show that the radiated energy to the formation in poorly-bonded conditions is less than that in well-bonded condition. But the main lobe width of the radiant beams and steered angle in near-borehole formation can be controlled by adjusting the delay time between the neighboring array elements regardless of well-bonded or poorly-bonded conditions. Compared with acoustic field excited by one point source, the P-wave amplitude for formations in the steered direction can be intensified obviously, which can strengthen the reflection energy and enhance signal-to-noise ratio of the received signal and detectivity fundamentally. The technique of the directional radiating acoustic field to the formation can improve the resolving capability and reliability of exploring the casing external complex reservoirs.