Summary of Performance and Evaluations in the West Burkburnett Chemical Waterflood Project
Authors: Talash A.W. , Strange Lloyd K. 
Published: December 2007

In late 1973, Mobil Producing Texas and New Mexico Inc. and Mobil Research and Development Corp. initiated a cooperative, low-tension waterflood (LTWF) project in Mobil's West Burkburnett waterflood, Wichita County Regular field. TX. The LTWF project encompasses ten 20-acre, five-spot patterns. A low-concentration surfactant slug was injected from Oct. 1975 to June 1976, followed in turn by biopolymer and freshwater drives. Tertiary oil production response first was noted near the completion of surfactant injection. and, to date, 17 of the original 20 producers are yielding incremental oil. Four producing wells outside the LTWF area have also shown some oil production response. The total tertiary oil production to the end of 1980 (actual) and to anticipated project termination in 1984 (projected) are estimated to be 238,000 and 320,000 bbl, respectively-equivalent to recovery factors of 17.6 and 24% of the OIP at project initiation.

These figures pertain to total oil production, since the project area would have been abandoned if the LTWF project had not been initiated. To the end of 1980, the oil recovery attributed directly to effects of the LTWF process is 105,000 bbl, that projected to the anticipated project termination in 1984 is 180,000 bbl. The corresponding recovery factors are 8 and 13%, respectively. This paper summarizes the engineering studies associated with this chemical waterflood field test.

Introduction

Mobil's West Burkbunett waterflood is about 4 miles southwest of Burkbunett (TX) and is classified in the Wichita County Regular field. The pool discover)/ well was C. Schmoker No. 1. completed in June 1912.

The producing sand is found at 1,600- to 1,800-ft depth and is designated the Gunsight sand in the Cisco series of Pennsylvanian age. The structure of the Gunsight sand in the area is lenticular, with the major axis running east and west. The sand dips approximately 250 ft from the south to the north. The producing sand is interspersed with shale and lenses into shale on all sides of the pool.

Waterflooding began in 1944 with a pilot flood developed on 20-acre five-spot patterns. Expansion to full development occurred during 1948–50. The current waterflood is a group of 100% Mobil working-interest leases being waterflooded on a cooperative 20-acre five-spot pattern arrangement.

In 1971, all the leases in the waterflood project either had become uneconomical to operate or were being projected to reach the economic limit by 1972 or 1973. Several leases on the east side of the project already had been abandoned. As a final step in exploitation. the project was evaluated for tertiary recovery by our LTWF multislug process. The functions of each of these slugs have been described by Foster and by Murphy et al. Plans were developed for application of the LTWF process in 10 adjacent, 20-acre patterns with 10 injectors, 20 producers, and 2 observation wells. This 200-acre development is shown in Fig. 1 as the enclosed area on a partial field map. Mobil Producing Texas and New Mexico operated the project, with personnel from Mobil Research and Development serving as technical consultants.

The LTWF project began in Nov. 1973 with a freshwater preflush. Injection of the surfactant slug started in Oct. 1975 and ended in June 1976. This was followed by a polymer drive until April 1978. Since then, fresh water has been injected and is continuing. The injection schedule of this chemical flood is summarized in Table 1. From 1974 through 1977, an injection rate of approximately 3,000 B/D into 10 injectors was being maintained.

JPT

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