Stimulation Treatment Design For The Delaware Basin Ellenburger
Authors: Crenshaw P.L. , Flippen F.F. , Pauley P.O. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the 43rd Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Houston, Texas, September 29-October 2, 1968. 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 OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
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Abstract
Stimulation of the 15,000-ft. to 23,000-ft. wells in the Delaware Basin is complicated by a producing formation thickness up to 1600 ft. and bottom-hole temperatures up to 360 degrees F. The naturally fractured carbonate rock with an absence of shale or sandstone barriers makes it difficult to control the placement of stimulation fluids. placement of stimulation fluids. Special perforating patterns and diverting agents have been successful in permitting controlled fluid flow into the desired zones. Treatment Evaluation Logs have been used to define the zones of treatment and subsequent production so that engineered treatment design production so that engineered treatment design has evolved from the previously derived theories regarding the fracture-acidizing process of stimulation. process of stimulation. Large volumes of acid are being used to treat these wells, so that engineered treatment design is necessary to justify these expenditures. Productivities of the wells are improved Productivities of the wells are improved to the extent that the treatments are warranted, and the productivity to be expected after the treatment can be estimated beforehand.
The factors involved in treatment design are discussed and the method of treatment design is given.

Introduction
The Delaware Basin and Val Verde Basin areas of West Texas are contributing gas production from various formations in an production from various formations in an ever-increasing number of fields (Fig. 1). At the present time, however, the Ellenburger is the formation predominantly being explored. According to specific locality, gas production from this formation occurs at depths from 10,000 ft. to more than 23,000 ft. Bottomhole temperature will also vary from less than 200 degrees F to more than 350 degrees F. Those reservoirs creating the most interest at present are the deeper ones below 15,000 ft. and they are the subject of study in this paper.
With very little exception, indicated field structures and traps are associated with faulting of some form. The prolific producing intervals are associated with good natural fracture development, and those sections without this development have generally shown poor production. poor production.