Finite Element Modeling of Downhole Sources and Receivers

40828 November 13, 1996 TomoSeis, Inc. While seismic data are used to determine the presence and extent of underground oil and gas reservoirs, their interpretation is very difficult. For example, it is crucial to know whether features observed in the recorded data are associated with the earth or with the data acquisition system. Issues of particular interest are the radiation/reception patterns of downhole sources/receivers and their change with frequency, the generation of tube waves in the source well, the ability of tube-wave attenuators to effectively shield the receiver arrays from receiver-well tube waves, the types of wave modes that sources generate, the relative amounts of each mode in the total produced/recorded wavefield, and the ability of the receivers to operate through tubing. This project will develop modeling software that will allow the numerical simulation of downhole sources and receivers and their study for equipment design and data interpretation purposes. Tests will determine the accuracy of the code in describing the behavior of the Resonant Cavity Piezoceramic source both in the air and in the borehole environment. Phase II will develop a commercial software package with the flexibility to simulate a large number of downhole source/receiver systems currently in use or under development. Anticipated Results/Potential Commercial Applications as described by the awardee: Improved understanding of downhole sources/receivers should enhance the potential of borehole geophysics for better imaging and production of oil and gas reservoirs. The commercial software package for downhole source/receiver simulation should be useful to oil and service companies in equipment development and data interpretation.