Development of Microseismic Methods to Determine Hydraulic Fracture Dimensions. Final Report, 1 December 1987-30 November 1989

摘要

A microseismic technique was developed, evaluated, and established to determine the depth of the top and bottom of a fracture treatment zone and is being offered as a commercial service. A proof-of-concept experiment at SFE No. 3 showed that the microseismic height technique gives a better estimate of the average fracture height than numerous cased hole logs. A U.S. patent on the method has been granted and assigned to GRI. A new application of reentering previously fractured wells was demonstrated in both the SFE No. 2 and 3 wells with height surveys four months after the main fracture treatment in each well. The application can lead to an expanded market area for the microseismic monitoring technique. A new significant class of low-frequency signals has been observed. It is anticipated that research with these signals can provide an estimate of the length of the fractured zone. The ambient microseismic background in the remote wells is 10 to 40 nm/s. In the presence of the noise level, signals from fracture treatments may not be detected at ranges greater than 500 to 1000 ft.