Drilling And Completion Practices Developed For The El Paistle (Deep) Field Kenedy County, Texas
Authors: Davis Homer L. 
Published: December 2007

This paper was prepared for presentation at the 47th Annual Fall Meeting of the Society of Petroleum Engineers held in San Antonio, Tex.,Oct. 8–11, 1972. Permission to copy is restricted to anabstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by who 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 discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

The El Paistle (Deep) Field is a deep, abnormally pressured gas field located in Kenedy County, South Texas. A combination of factors make drilling and completing wells in this field as difficult a challenge as can be found in nearly any drilling area in the world today. These factors include abnormal porepressures which routinely require mud weights pressures which routinely require mud weights of 18.0 to 19.0 ppg to control; short, difficult to detect pore pressure transition zones; and bottom hole temperatures in excess of 310degrees Fahrenheit at 15,000 feet.

Development in the field has now span neda nine-year period. During the early stages, four out of the eight wells drilled in the field did not achieve the desired objectives due to the harsh drilling conditions. Since then, eleven additional wells have been drilled in the field with only one failing to achieve the desired objective. Improvements made in drilling techniques, well planning, supervision, well control practices, cementing procedures and well completion procedures are procedures and well completion procedures are reviewed in depth in the paper.

While some problems remain to be solved, drilling in the El Paistle (Deep) Field has progressed to the point where it can now be progressed to the point where it can now be considered almost routine.

Introduction

El Paistle (Deep) Field is located in South Texas, approximately 35 miles southeast of Kingsville in Kenedy County (see Figure 1).The field is formed by a northeast-southwest trending anticlinal feature controlled by several down-to-basin faults. Commercial sweet gas production occurs in the upper "Ab" Marine Frio formation which extends from approximately13,000 to 15,000 feet. This section consists mainly of thick, massive deltaic sands of early Miocene age with good porosity but fairly low permeability. permeability. Early definition of the field was made difficult by the relatively high degree of faulting and the erratic depositional characteristic of the sands. Combined with the difficult stratigraphy was the variation in pore pressure sometimes encountered from well to well. pressure sometimes encountered from well to well. Even when good zone correlation was established, there was no guarantee that pore pressures would also correlate. These factors caused nearly every well to be considered a step-out or field wildcat, although they were drilled as field development wells.