Progress Report On Acoustic Amplitude Logging For Formation Evaluation

Publication Rights Reserved This paper is to be presented at the 37th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in Los Angeles, California, October 7–10, 1962, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations unless the paper is specifically released to the press by the Society Publications Committee Chairman or the Executive Secretary on his behalf. Such abstract should contain appropriate, conspicuous acknowledgment. Publication elsewhere after publication in Journal of Petroleum Technology is granted on request, providing proper credit is given that publication and the original presentation of the paper. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office; it will be presented at the above meeting with the paper and considered for publication in Journal of Petroleum Technology. Examples of acoustic amplitude logs have shown the application in obtaining more efficient well completions by locating any natural fracturing and confining any necessary well treatment to that interval. Since early 1961 logs have been run in practically all areas and all types of formations. Investigation into the theory of acoustic transmission of all arrivals through various formations indicate the possibility of a usable correlation of signal amplitude with matrix permeability. Although only a limited amount of field data is available at present, indications are that a usable matrix permeability anomaly does exist. The matrix permeability effect and other possible useful information from the acoustic signal are being studied by different recordings of the full receiver signal preferably on cored wells to allow determination of the most useful information and the best means for recording. Introduction In early 1961 the Fracture Finder was introduced commercially to the industry, making use of the acoustic transmission of the formation to locate optimum completion intervals. As described in a previous paper the signal amplitude is reduced because of the large reflection of energy at density interfaces resulting from naturally existing formation fractures. Test well data was shown where the signal was reduced 23 per cent by a horizontal interface between machined limestone blocks. Although it is probable that this reduction will depend upon the fracture width and area of bearing surfaces across the fracture, the degree of reduction can be used as an indication of the extent of fracturing. This log has since been run in practically all areas and has materially aided in selecting optimum completion intervals. In a number of formations the interval to be perforated can be reduced and any required treatment confined to that interval most susceptible to such well treatment.