The Determination of Direction and Length Of Hydraulically Induced Fractures In Petroleum Reservoirs: A Field Experiment
Authors: Shuck L.Z. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the 49th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Texas, Oct. 6–9, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Hydraulic fracturing of oil and gas bearing sandstone formations to enhance recovery is still being done today without any means of determining the actual types, lengths, or directions of fractures induce away from the wellbore. The mechanics of hydraulic fracturing processes affecting the acoustic mapping of fractures, the associated crack and wave propagation phenomena, monitoring system requirements, an example of a monitoring system used, and field experiments conducted to date by the Morgantown Energy Research Center, U.S. Bureau of Mines are discussed.
Applications of the fracture mapping technique, if proven successful could lead to improved well location design and fracturing treatments for more efficient petroleum and natural gas recovery, solution mining, in situ coal gasification and liquefaction, subsurface waste disposal, oil shale and geothermal energy extraction, and perhaps others.
Preliminary analysis of the data indicates that the fractures propagate in discrete phases or arc lengths during which sufficient acoustic emissions occur to allow the fractures to be mapped, and that the best bandwidth for monitoring the acoustic emission may be the 80 to 500 Hz range.

Introduction
Hydraulic fracturing of oil and gas bearing formations to increase recovery has been a practice since the late 1940's. Although many practice since the late 1940's. Although many schemes of calculating fracture lengths and predicting the directions have been devised, no predicting the directions have been devised, no direct means of measuring the number, types, lengths, directions, or rates of growth of induced fractures exists today. Wellbore post-fracture measurements, including impression post-fracture measurements, including impression packers, are presently the best means of direct packers, are presently the best means of direct measurement of induced fracture orientations. These observations, however, are not necessarily valid a few inches away from the wellbore. Further development of hydraulic fracturing technology depends upon a more immediate means of measuring results. Accurate and immediate measurement of the fracture directions for only a few wells in a new reservoir could allow systematic development for maximum and more economical recovery.