Miscible Drive Field Applications in the Panhandle Field

Abstract

Introduction The Hughey B lease, the north one-half Section 129, Block 3, T&GN RR Survey, Gray County, Tex., is the location of a pilot project of slug LPG injection to improve the existing gas drive. The Hughey B lease is one of the leases in the West Pampa Repressuring Assn. that has been returning produced gas to the Brown Dolomite reservoir since 1946. The pilot project consists of two input wells that were gas injection wells and the 12 producing wells that are direct or diagonal offsets to the input wells. Table 1 contains information on the pilot area. The LPG slug was taken from the Cities Service gasoline plant approximately 1 mile west of the Hughey B lease. In the spring of 1957, it was apparent that there would be products produced at the plant in excess of market demand and storage facilities. Plans were made to utilize this otherwise wasted material to test the recovery possibilities of LPG injection in this type reservoir. Laboratory research on samples of LPG and Brown Dolomite crude found no adverse effects on mixing the two liquids. Displacement tests on a core are being run to aid in the operation of the pilot project. LPG - Gas Injection It was determined that slug LPG injection would be the most advantageous mechanism and in July, 1957, liquid butane injection started in Hughey B No. 10. LPG injection continued until a slug consisting of 76,076 bbl of butane and 53,074 bbl of propane had been injected. On Nov. 13, LPG injection ceased in Hughey B No. 10 and gas injection resumed at approximately 500 Mcf/D. LPG injection in Hughey B–23 was started immediately and a volume of 50,412 bbl of butane and 50,433 bbl of propane was injected to Jan. 22, 1958. Gas injection was then resumed and the LPG injection in the pilot area was completed. To April 1, 1958, 230,625 bbl of LPG and 100 MMcf of gas have been injected into the pilot area since project initiation. The daily production performance from the Hughey B lease has always been erratic and well tests vary considerably. The best method of detecting stimulation of the producing wells in the pilot area has been by fluid-level surveys. Static fluid-level surveys on two producing wells, Hughey B–4, the north offset, and Hughey B–11, the west offset to Hughey B–10, indicated approximately 800 ft more fluid than was present before the project started. Production tests on these wells gave Hughey B–4 82 BOPD, up 71 BOPD from the normal rate, and Hughey B–11, 96 BOPD, up 61 BOPD. Testing continues on the lease and at latest report, three more wells are producing some increased oil. Further testing will show how much these wells are stimulated. Increased oil production to April 1, 1958, is estimated at 8,930 bbl. The stimulation of producing wells is believed to be justification for assuming that this project will recover oil that would not be produced by continuing the previous recovery mechanism. The volume of this oil cannot be estimated at this time and for this reason, no economic evaluation can be made.