Slaughter field is a 100,000-acre oil and gas producing area in Hockley, Cochran, and Terry counties on the South Plains of West Texas and on the geological feature known as the North Basin platform. The billion-barrel field, driven by solution gas in its primary recovery, produces from a stratigraphic trap in the San Andres formation. Situated south of the prolific Levelland field, Slaughter joins it on the west and east. However, the two fields are separated in the center by a two-mile-deep and twenty-five-mile-wide unproductive strip on either side of the Hockley-Cochran county line. Because of this unique feature, wells which appeared to be staked in the middle of two large fields found no oil or gas production, because reservoir rock was lost there due to anhydrite plugging. During its early years in the late 1930s Slaughter was regarded as two separate fields called Duggan (on the west) and Slaughter (on the east). After evidence proved that both fields produced from the same formation, the Railroad Commission combined them under one field regulation and called both areas Slaughter field. The land around Slaughter field first attracted oil prospectors in the late 1920s. A longtime California operator, Honolulu Oil Company, began exploring for West Texas oil in 1927, but the Great Depression halted prospecting in the area through 1935. In late winter and early spring of 1936 two oil operators started prospecting separately and with different exploration techniques, one in Cochran County and the other in Hockley. In February 1936 Cascade Petroleum Company, with its partners Devonian Oil Company and Honolulu, leased several thousand acres for drilling in Cochran County, intending to use traditional geological data to find oil. In April Texas Company (later Texaco) announced plans to drill in southwestern Hockley County, needing only small blocks of leases to experiment with its new geophysical equipment and interpretations.
Cascade, Devonian, and Honolulu, agreeing to a three-way drilling venture, acquired 890 acres in League 54 and 2,495 acres in League 55. They spudded the Duggan et al. No. 1-A six miles west of the Hockley county line in Cochran County. The well was drilled with rotary tools to 2,297 feet, and then cable tools, which allowed closer observation of drilling samples, were used to complete it to a total depth of 5,098 feet in the San Andres formation on October 29, 1936. The well was plugged back to 5,068 feet, where its potential was tested at 396 barrels of oil per day, and it was hailed as the discovery well in the Duggan field. The Railroad Commission based allowables for the new field 75 percent on acreage and 25 percent on potential. Although the success of the Duggan No. 1-A caused leasing excitement that extended southeast into Terry County, no offsetting well was completed in 1936. The one-well field reported production of 3,747 barrels of oil at the end of the year. In 1937 four wells were drilled, but three were dry holes. The one producing well, the Inglewright and Fogelson No. 1 Houston, was northwest of the Duggan well and came in with 388 barrels of oil per day after it was plugged back to 5,055 feet from a total depth of 5,060 feet. The No. 1 Houston increased the daily average field production to 100 barrels of oil. Although a third producer, the No. 2 Houston, located southwest of the discovery well, was ready for completion at the end of 1937, Duggan field ended the year with only two wells. The field consisted of an estimated 9,000 proved acres and yearly production of 34,040 barrels of oil. Field development continued slowly because no pipeline existed to carry crude to market. Operators, who had to truck their production to the Humble carrier in Bennett field of Yoakum County, had little incentive to drill more wells. Although some crude was sold to operators of small refineries in nearby towns, it was a limited market.
While Duggan field was slowly developing in 1937, Texas Company brought in its No. 1 Bob Slaughter, staked in southwestern Hockley County, twelve miles east and slightly south of the Duggan well. The Slaughter well was completed on April 6, 1937, after drilling intermittently for almost a year and being plugged back to 5,023 feet from 5,030 feet. It flowed 512 barrels of oil per day. Since it appeared that the No. 1 Slaughter was not part of Duggan field, its producing area was called Slaughter field, and allowables were based 50 percent on acreage and 50 percent on potential. Spacing for wells was divided into 17.7-acre basic units, but lease owners were allowed the discretion of using up to 35.4 acres per unit. In September 1937 the Stanolind No. 1 Slaughter was completed in Hockley County. After it was shot with nitroglycerin, the well flowed 432 barrels of oil per day from a depth of 4,975 feet. Between September and December 1937 a third successful well, the Texas No. 2 Slaughter, was staked between the two earlier wells. The No. 2 Slaughter was acidized before flowing 532 barrels of oil on a potential test. By the end of the year the field reported three producing wells, two dry holes, two drilling wells, and an estimated yearly production of 34,299 barrels of oil. In May 1938 the Texas Company No. 1-A Mallet Land and Cattle Company, staked in southeastern Cochran County six miles southeast of the Duggan area and eight miles southwest of the Slaughter pool, came in. Since it was between the two fields, the Mallet discovery pointed toward a possible connection between the Duggan and Slaughter sectors. Throughout the summer and fall of 1938 drilling continued, as Slaughter field was extended four miles to the north by the Sid W. Richardson No. 1 Slaughter and one mile to the east by the Gulf Oil Company No. 2 Mallet. The Snowden and McSweeney No. 1 Slaughter, located four miles east and one mile south of the Texas discovery well, defined the southeastern limit of the field. Although these wells were prolific, the lack of pipeline outlets in the Slaughter area, as in the Duggan, gave little incentive for additional field development. Slaughter pool ended 1938 with 12,000 proved acres and yearly production of 121,132 barrels of oil from ten wells.
Like Slaughter field, the number of proved acres in Duggan was increased in 1938. The Texas No. 1 Mallett pushed out the southeastern edge of the field by five miles, and the Devonian et al. No. 1-C-8 Duggan expanded it three miles to the south. Duggan field reported the completion of five producing wells during the year, bringing the total number of successful wells to eight. No gas wells and no dry holes were drilled in the year. At the end of the year Duggan reported 12,000 proved acres and cumulative production of 160,824 barrels of oil. Both Duggan and Slaughter fields found encouragement for additional field development in 1939, when South Plains Pipe Line Company built a carrier from the fields to Motor Fuel Refinery at Levelland, Texas. A second line connected the field to the Aloco and Humble line at Wasson field. During 1939 Duggan produced 172,688 barrels of oil from fourteen wells held by three operators. Slaughter reported yearly production of 494,635 barrels of oil from sixty-six wells that were operated by ten producers. Four of those operators-Honolulu, Sid W. Richardson, Stanolind Oil Company, and Western States Gasoline Company-held most of the Slaughter production. With the South Plains line and the Aloco connection to move crude from both the Duggan and the Slaughter areas, drilling continued to increase in 1940. During the year Magnolia Pipe Line Company built a gathering system in Slaughter field and a fifty-one-mile, eight-inch carrier to Seminole, Texas, with a capacity of 6,000 barrels of oil per day. Texas-New Mexico Pipe Line Company completed a line to Midland, Texas, which could move 8,000 barrels of oil per day. Expansion in both Duggan and Slaughter fields consisted of gradual and low-risk development of the space that separated them. Operators were so successful in linking the producing sectors that on December 1, 1940, the Railroad Commission ruled that the two fields produced from a common reservoir. The commission officially joined the 54,500 proved acres of the Duggan and Slaughter areas into one field called Slaughter. Before merging with Slaughter field, Duggan produced 211,660 barrels of oil during 1940 from thirty-one wells held by seven operators. Slaughter field reported its 1940 production as 951,422 barrels of oil from 168 wells. The yearly combined production of both pools was 1,163,082 barrels of oil.
During 1941 Slaughter field developed generally in a northward direction, but the field was also enlarged by wells that pushed its boundaries to the northeast, west, and south. One deep test by Atlantic Company attempted to find a deeper pay zone by drilling to 7,000 feet, but no evidence of oil was found below the 5,000-foot Slaughter-producing horizon. When a fourth pipeline was built in 1941 by Sid W. Richardson from Slaughter to Wasson field in Gaines County, yearly production sharply increased by fourfold to 4,856,434 barrels of oil from 851 wells. The 57,014 proved acres of the field made it the second-largest oil-producing area in the state. From 1942 through 1945 the field continued to build toward peak production. Its 1942 yield of 7,535,675 barrels of oil from 1,201 wells was greatly exceeded by the 11,241,484 barrels of oil from 1,519 wells reported in 1943. Also in 1943, as the field continued to balloon, Honolulu Oil Corporation constructed a small camp for its employees in Cochran County. Production for 1944 doubled the 1943 figure and that number enlarged again in 1945, the peak production year, when 23,824,107 barrels of oil came from the 1,893 wells in the field. The spur in drilling and production in the early 1940s resulted from a ruling by the Railroad Commission that permitted the drilling of additional wells in each lease of the field. Cumulative production at the end of 1945, which ended the first decade of field production, was a staggering 71,120,744 barrels of oil.
Throughout the second half of the decade, the maturing field remained strong. In 1946 Slaughter field produced gas for the first time when it reported a yield of 5.5 million cubic feet of gas and 182 barrels of condensate from a total of six well. In October 1947 operators in the field successfully opposed the combining of Slaughter and Levelland fields, arguing that the two did not connect and that they produced from separate reservoirs. Gas yields increased through 1948, when they peaked at over 159 million cubic feet, ending the decade with cumulative production of 354.7 million cubic feet. Throughout the remainder of the decade yearly crude totals declined slowly, but cumulative production at the end of 1949 had more than doubled that of 1945 for a reported 144,196,018 barrels of oil. Although production of both crude and natural gas peaked in the 1940s, the field remained viable and maintained efficiency in production from the 1950s into the 1990s because operators initiated both secondary and tertiary projects to strengthen yields. Although waterflooding was introduced to claim oil left in place by primary recovery, it had mixed results in Slaughter field, where reservoir communications is missing in many sections and where individual porous zones were not completed separately in some wells. In September 1957 Great Western Drilling Company launched the first secondary recovery project in the field when it pumped salt water into the Glimp Unit. By 1958 the Railroad Commission had authorized seven secondary and tertiary recovery projects of different types. Tertiary recovery, using gas injections and a combination of gas and water floods, managed to force out as much as 62 percent of oil left in place by primary and secondary attempts. Between 1976 and 1984 Amoco Production Company conducted a successful flood project in Hockley County, using carbon dioxide and hydrogen sulfide, which were inserted with an alternating gas-water injection followed by chase gas. In 1989 Slaughter Estate Unit in the southeastern field realized significant tertiary recovery from a carbon dioxide flood. At the end of 1992 the mature field reported an annual production of 16,637,389 barrels of oil from 2,535 wells and 7,950,000 cubic feet of gas from two wells. Expectations for future yields from the Slaughter reservoir were set at 96.6 million barrels of oil at the end of 1993. In its fifty-eighth year of operations, on March 31, 1994, Slaughter field reported a cumulative figure of 1,116,868,473 barrels of oil.