Deeper-pool Tests Research Articles

Developments in Pennsylvania in 1960

During 1960, exploration in Pennsylvania resulted in the discovery of 1 new gas field, 8 new gas pools, and 1 deeper pool. It also extended several gas-producing areas, and established a new producing depth record in the state. After drilling a dry hole to the Gatesburg formation (Upper Cambrian) in each of its 2 offshore blocks, the New York State Natural Gas Corporation surrendered its acreage. The new producing-depth record was established by the Robert I. Snyder well No. 1 in Somerset County when gas was found in the Oriskany at 8,574 ft. The well had an initial open-flow after fracturing of 1,572 MCF of gas at a rock pressure of 3,293 psi in 44 hrs. Deep exploration (Middle Devonian or older) found all of the new pools and the one new field. Of the unsuccessful wildcats, 12 were new-field wildcats and 6 were new-pool wildcats. Three deeper pool tests were unsuccessful as were 10 outposts. One new-field wildcat, 8 new-pool wildcats, 1 deeper-pool test, and 3 outposts were successful. There were 61 development gas wells completed and 21 dry holes. The greatest density of deep drilling occurred in Clearfield County. There were 126 deep wells completed in Pennsylvania in 1960 with a total footage of 851,347 ft. Of the 126 wells, 74 were gas wells and 52 were dry holes. Secondary-recovery projects in the Bradford field and the development drilling in the gas fields dominated the shallow-sand drilling activity during 1960. No new shallow-sand oil or gas discoveries were made. In all, 745 shallow-sand wells were completed. Of these, 175 were gas wells, 24 were oil wells, 47 were dry holes, 2 were drilled for underground gas storage, and 497 were drilled in connection with secondary-recovery operations. In addition to the 745 wells, 42 shallow-sand wells were deepened. The total footage of the new and deepened wells was 1,578,933 ft. Oil production increased from 5,760,000 bbls. in 1959 to 5,942,000 bbls. in 1960. Proved oil reserves were estimated at 108,028,000 bbls. on December 31, 1960. Gas production increased from 118,862,000 MCF in 1959 to 119,671,000 MCF in 1960. Gas reserves were estimated at 1,192,132,000 MCF at the end of the year. Distillate produced in 1960 amounted to 67,000 bbls. The total footage drilled, both shallow and deep, was 2,430,280 ft.

Exploratory Drilling in 1960

This report, the sixteenth based on data gathered by the Committee on Statistics of Exploratory Drilling, is the twenty-fifth annual summary on the subject published in the Bulletin. Frederic H. Lahee prepared this statistical analysis and wrote the annual article for twenty consecutive years. Graham B. Moody prepared the report for exploratory drilling for 1956, and B. W. Blanpied prepared it for 1957, 1958, and 1959. This is the first report for the present chairman. During 1960, 11,704 exploratory holes were drilled in the United States; 2,189 of these produced some oil or gas representing 18.70% of all exploratory effort. There were 7,320 new-field wildcats, 745 of which produced some oil or gas, representing 10.18% of all new-field wildcats. New-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests) for 1960 totaled 1953 holes, 616 or 31.54% of which produced some oil or gas. There were 2,431 outposts; 828 of them, or 34.060%, produced some oil or gas. The total exploratory footage drilled in the United States in 1960 was 55,830,684 ft. in the 11,704 holes, or 4,770 ft. per hole. These figures compare with 63,252,521 ft. drilled in 13,191 exploratory holes, with an average depth of 4,795 ft. in 1959. For the second time data are presented on natural gas reserves in the 17-States Area by years, for discoveries having 6 years of development history. Only about 2% of all new-field wildcats discover a profitable field although 11-12% are successful in that they produce some oil or gas. For the thirteenth time, we are presenting data on Canada and Mexico.

Exploratory Drilling in 1959

This report, the fifteenth based on data gathered by the Committee on Statistics of Exploratory Drilling, is the twenty-fourth annual summary on the subject published in the Bulletin. Frederic H. Lahee prepared this statistical analysis and wrote the annual article for twenty consecutive years. Graham B. Moody prepared the report for exploratory drilling for 1956. This is the third report for the present chairman. During 1959, 13,191 exploratory holes were drilled in the United States. Of these 7,031 were new-field wildcats, 3,355 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests) and 2,805 were outposts. Among the new-field wildcats, 772 were successful, among the new-pool tests 941 were successful, and among the outposts 901 were successful. The total exploratory footage drilled in the United States in 1959 was 63,252,521 feet in the 13,191 holes, or 4,800 feet per hole. These figures compare with 61,483,911 feet drilled in 13,199 exploratory holes, with average depth of 4,661 feet in 1958. For the first time we are presenting data on natural gas reserves in the 17 States Area by years, for discoveries having six years or more of development history. For the twelfth time, we are presenting data on Canada and Mexico.

Petroleum Developments in Mexico in 1959

Four hundred forty-one wells were drilled in Mexico during 1959 as compared with 379 drilled the preceding year. The average depth per well was increased to 7,035 ft. as compared with an average of 6,958 ft. per well during 1958. During the year of 1959, 133 wells were classified as exploratory holes, of which 82 were new-field wildcats, resulting in the discovery of 11 new gas and oil fields. Other exploratory holes were classified as follows: 9 new-pool wildcats, 9 deeper-pool tests, 8 shallower-pool tests, and 25 extension wells; 31 of these exploratory holes were completed as producers. Of the total number of wells, 298 were successful. The new fields discovered were located as follows: 1 in the Eocene trend in Northeast Mexico, 5 in Cretaceous and Jurassic limestones and calcarenites in the Tampico Embayment, and 5 new fields in Miocene sands in the Isthmus and Tabasco region, one of which is an off-shore prospect. The main exploratory effort, as in previous years, was concentrated along the coastal plain of the Gulf of Mexico where all the producing fields are located; however, seismic work in Baja California and gravity work in the Yucatan Peninsula and Northeastern Chihuahua were continued. One test was drilled to the Cretaceous in Northeast Mexico, and 5 tests were drilled to explore the productivity of the Upper Jurassic and Lower Cretaceous formations in the Tampico Embayment. In the Veracruz Embayment, as in the past year, drilling activities decreased considerably as only 4 wells were drilled in search of oil: 2 were drilled to the Middle Cretaceous, as yet unproductive in this area and 2 to the Eocene and Oligocene. Crude oil and distillate production in 1959 was 105,758,473 bbls., an increase of 9.5% over the previous year. Total gas production was 329,363,504 MCF, an increase of 79.7% over 1958.

Exploratory Drilling in 1958

This report, the fourteenth based on data gathered by the Committee on Statistics of Exploratory Drilling, is the 23d annual summary on the subject published in the Bulletin. Frederic H. Lahee prepared this statistical analysis and wrote the annual article for 20 consecutive years. Graham B. Moody prepared the report for exploratory drilling for 1956. During 1958, 13,199 exploratory holes were drilled in the United States and Alaska. Of these, 6,950 were new-field wildcats, 3,191 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 3,058 were outposts. Among the new-field wildcats, 786 were successful, among the new-pool tests, 809 were successful, and among the outposts 972 were successful. The total exploratory footage drilled in the United States and Alaska in 1958 was 61,483,911 ft. in the 13,199 holes, or 4,661 ft. per hole. These figures are comparable with 69,136,266 ft. drilled in 14,707 exploratory holes, with average depth of 4,701 ft. in 1957. For the 11th time, we are presenting data on Canada and Mexico.

Exploratory Drilling in 1957

This report, the 13th based on data gathered by the Committee on Statistics of Exploratory Drilling, is the 22d annual summary on the subject published in the Bulletin. Frederic H. Lahee prepared this statistical analysis and wrote the annual article for 20 consecutive years. Graham B. Moody prepared the report for exploratory drilling in 1956. During 1957, 14,707 exploratory holes were drilled in the United States and Alaska. Of these 8,014 were new-field wildcats, 3,476 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests) and 3,217 were outposts. Among the new-field wildcats, 872 were successful; among the new-pool tests, 854 were successful; and among the outposts, 1,084 were successful. The total exploratory footage drilled in the United States and Alaska in 1957 was 69,136,226 ft. in the 14,707 holes, or 4,701 ft. per hole. These figures compare with 73,981,176 ft. drilled in 16,173 exploratory holes, with an average depth of 4,574 ft. in 1956. Our data show that oil production has been found in the state of Washington and in Alaska for the first time. For the tenth time, we are presenting data on Canada and Mexico.

Developments in Oklahoma in 1957

Exploratory drilling decreased 10.5% in Oklahoma during 1957 with 19.7% success; development drilling decreased 21.9% with 67.7% success. Significant new-field discoveries include the North Carter of Beckham County, the Southwest Enville of Love County, the Brent of Sequoyah County, and the dual Cromwell and Wilcox sand gas discovery in southern Okmulgee County. Continued emphasis on stratigraphic exploration, coupled with deeper drilling and favorable returns from gas, resulted in active exploration in nearly every section of the state. The widespread exploratory and development interest has led to approximately 55% of the state being under lease. A 20,426 ft. unsuccessful deeper-pool test (No. 170, Fig. 1) drilled in the Cement pool of Caddo County, holds the new depth record for the state. Seismic activity decreased slightly as compared with previous years. Secondary recovery and production from unallocated or stripper oil fields continue to account for more than half the state's oil production.

Exploratory Drilling in 1956

This report, the 12th based on data gathered by the Committee on Statistics of Exploratory Drilling, is the 21st annual summary on the subject published in the Bulletin. Frederic H. Lahee prepared this statistical analysis and wrote the annual article for 20 consecutive years. The current writer agreed to act as chairman of the Committee for one year because no one else was available. He is pleased indeed to announce that B. W. Blanpied of the Gulf Oil Corporation will be chairman for the coming year. During 1956, 16,173 exploratory holes were drilled in the United States. Of these 8,709 were new-field wildcats, 3,841 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 3,623 were outposts. Among the new-field wildcats, 868 were successful; among the new-pool tests 1,021 were successful; and among the outposts 1,207 were successful. The total exploratory footage drilled in the United States in 1956 was 73,981,176 ft. in the 16,173 holes, or 4,574 ft. per hole. These figures compare with 69,173,209 ft. drilled in 14,937 exploratory holes, with an average depth of 4,631 ft. in 1955. For the ninth time, we are presenting data on Canada and Mexico. End_Page 989------------------------------

Developments in Michigan in 1955

Both exploratory and development drilling, in Michigan during 1955, reflected a slight decline in comparison with the figures of 1954. A total of 203 exploratory wells was completed in 1955 as compared with 253 completed in 1954. There were 13 discoveries in 1955: 11 were oil wells and 2 were gas wells. These were classified as 7 new-field wildcats, 4 shallower-pool tests, and 2 deeper-pool tests. Total footage drilled during the year was 1,536,441 feet as compared with 1,485,711 feet drilled in 1954. Oil production showed a decline in 1955 of approximately 3/4 million barrels or 2,000 barrels per day. Gas production in 1955 increased considerably over 1954. Leasing activities declined sharply in Michigan during 1955. The State of Michigan, during 1955, revised its own oil and gas lease from a 5-year term to a 10-year term. Core-drill exploration increased slightly over 1954 totals with the majority of the work being done in the Southeastern district. Exploration activities in Michigan for 1956 are expected to maintain a level comparable with 1955. A trend toward deeper drilling is expected in 1956.

Exploratory Drilling in 1955

This report, the eleventh based on data gathered by the Committee on Statistics of Exploratory Drilling, is the twentieth annual summary on the subject prepared by the author. A brief history of this undertaking is presented. With many thanks to those who have assisted him, and to the Sun Oil Company and the Humble Oil and Refining Company, the author now bows out as chairman of the C.S.E.D. and leaves the task to his successor, Graham B. Moody, who has long served as vice-chairman of this committee and as chairman of the California subcommittee. During 1955, 14,937 exploratory holes were drilled in the United States. Of these 8,104 were new-field wildcats, 3,629 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 3,204 were outposts. Among the new-field wildcats, 918 were successful; among the new-pool tests, 1,069 were successful; and among the outposts, 1,118 were successful. The total exploratory footage drilled in the United States in 1955 was 69,173,209 feet in the 14,937 holes, or 4,631 feet per hole. These figures are comparable with 59,581,038 feet drilled in 13,097 exploratory holes, with an average depth of 4,549 feet in 1954. For the eighth time, we are presenting data on Canada and Mexico. Because the summary of the data gathered annually by this committee is the most reliable analysis available of the Industry's exploratory drilling for oil and gas, and because the facts presented in this analysis demonstrate the high degree of risk in exploratory drilling and, therefore, the need and fairness of the 27½ per cent depletion allowance, the work of the committee must go on without interruption in time or omission of any district.

Exploratory Drilling in 1954

This is the tenth annual report on data gathered by the committee on statistics of exploratory drilling. During 1954, 13,097 exploratory holes were drilled in the United States. Of these 7,380 were new-field wildcats, 3,085 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 2,632 were outposts. Among the new-field wildcats, 902 were successful; among the new-pool tests, 883 were successful; and among the outposts, 923 were successful. The total exploratory footage drilled in the United States in 1954 was 59,581,038 feet in the 13,097 holes, or 4,549 feet per hole. These figures compare with 60,702,371 feet drilled in 13,313 exploratory holes, with an average depth of 4,560 feet, in 1953. For the seventh time we are presenting data on Canada and Mexico. Because the summary of the data gathered annually by this committee is the most reliable analysis available of the Industry's exploratory drilling for oil and gas, and because the facts presented in this analysis demonstrate the high degree of risk in exploratory drilling and, therefore, the need and fairness of the 27½ per cent depletion allowance, the work of the committee should most certainly go on without interruption in time or omission of any district.

Developments in North Mid-Continent in 1954

Approximately 145 new fields and pools were discovered in Kansas during the year 1954, most of which were named as new discoveries by the Nomenclature Committee of the Kansas Geological Society. The total of 145 discoveries includes 124 oil discoveries, 20 gas discoveries, and one discovery for both oil and gas. In addition there were 15 discoveries of deeper production in previously producing pools; there were 37 discoveries of shallower production in previously producing pools. Of the total discoveries, 30 were of the new-field classification, the remainder new-pool discoveries. Kansas produced 118,309,260 barrels of oil, 4,613,869 barrels of natural gasoline and LPG, and 405,841,947 MCF of gas in 1954. There were no successful wildcats in Iowa, Missouri, or Nebraska; however, the latter state did have one successful deeper-pool test, in Richardson County.

Developments in West-Central Texas in 1954

Development during 1954 was somewhat less than in 1953. In all, 2,288 development wells were drilled as compared with 2,624 in 1953. Exploratory drilling was up approximately 10%, increasing from 1,011 wells drilled in 1953 to 1,107 during 1954. The number of successful new-field wildcats dropped from 123 in 1953 to 117 in 1954. The continued high rate of development drilling during the past 2 years, along with the rejuvenation of old producing fields with sand-fracturing methods, has resulted in establishing a new oil production record of 46,241,638 barrels during 1954. The previous record was the 42,860,662 barrels of oil produced in 1953. Geophysical activity increased slightly during 1954, with Fisher and Nolan counties accounting for the increase. Subsurface geological methods were credited with more than 80% of the new-field discoveries. Callahan, Shackelford, Stephens, and Throckmorton counties led the district in the number of discoveries. Important new-field discoveries were EA field in Nolan County, A. C. Scott field in Callahan County, and Greathouse field in Throckmorton County. Skelly No. 3-B Boyd, sand discovery in the North Dora field of Nolan County, was the most important deeper-pool test drilled. This well, which had more than 120 feet of net effective pay in the sand, gave impetus to the intense search for the prolific sand production found along the Cambrian trend north and south along the eastern side of Nolan County. The West-Central Texas District covers a 24-county area comprising Texas Railroad District 7-B (Fig. 1). All or part of six geological provinces (Fig. 1) are represented in this area. The six provinces have been previously described (FOOTNOTE 3) as to their boundaries, general stratigraphy, and type structures.

Exploratory Drilling in 1953

This is the ninth annual report on data gathered by the committee on statistics of exploratory drilling. During 1953, 13,313 exploratory holes were drilled in the United States. Of these 6,925 were new-field wildcats, 3,358 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 3,030 were outposts. Among the new-field wildcats, 774 were successful; among the new-pool tests, 924 were successful; and among the outposts, 982 were successful. The total exploratory footage drilled in the United States in 1953 was 60,702,371 feet in the 13,313 holes, or 4,560 feet per hole. These figures compare with 55,615,389 feet drilled in 12,425 exploratory holes, with an average depth of 4,476 feet, in 1952. For the sixth time we are presenting data on Canada and Mexico.

Exploratory Drilling in 1952

This is the eighth annual report on data gathered by the committee on statistics of exploratory drilling. During 1952, 12,425 exploratory holes were drilled in the United States. Of these 6,698 were new-field wildcats, 3,298 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 2,429 were outposts. Among the new-field wildcats, 741 were successful; among the new-pool tests, 888 were successful; and among the outposts, 706 were successful. The total exploratory footage drilled in the United States in 1952 was 55,615,389 feet in the 12,425 holes, or 4,476 feet per hole. These figures compare with 49,343,694 feet drilled in 11,756 exploratory holes, with an average depth of 4,197 feet in 1951. For the fifth time we are presenting data on Canada and Mexico.

Exploratory Drilling in 1951

This is the seventh annual report on data gathered by the committee on statistics of exploratory drilling. During 1951, 11,756 exploratory holes were drilled in the United States. Of these 6,189 were new-field wildcats, 3,062 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallow-pool tests), and 2,503 were outposts. Among the new-field wildcats, 684 were successful; among the new-pool tests, 851 were successful; and among the outposts, 680 were successful. The total exploratory footage drilled in the United States in 1951 was 49,343,694 feet in the 11,756 holes, or 4,197 feet per hole. These figures compare with 40,175,173 feet drilled in 10,306 exploratory holes, with an average depth of 3,898 feet in 1950. For the fourth time we are presenting data on Canada and Mexico.

Developments in Louisiana Gulf Coast in 1951

Drilling showed a 10.17 per cent decrease under 1950 with 1,007 wells being completed in 1951 as compared with 1,121 wells in 1950. Of the total wells drilled, 334 or 33.17 per cent were classified as exploratory and 673 or 66.83 per cent as field development wells. Successful completion rate of the exploratory wells was 36.53 per cent and of the development wells 75.18 per cent. There were 142 new-field wildcat tests drilled in 1951 which is a 3.52 per cent increase over last year. These new-field wildcats discovered 24 new fields, a success percentage of 16.9 per cent as compared with 13.9 per cent in 1950. Of the 24 new discoveries, 12 were oil, 10 gas condensate, and two gas. Ten of the discoveries were completed in the Miocene, 8 in the Oligocene, 4 in the Eocene, and one each in the Pliocene and Cretaceous. In 1951, there were 192 exploratory tests drilled on producing structures as compared with 135 similar tests in 1950. Of these, there were 90 new-pool wildcats drilled, of which 43 per cent were successful; 16 shallow pool tests, of which 87.5 per cent were successful; 45 deeper pool tests with 84.4 per cent successfully completed, and 41 outposts, of which 17.07 per cent were successfully completed. The most significant addition to reserves was the exploration on and around old producing areas. The Miocene trend contributed the greater part of new reserves. There were several dry exploratory tests which added knowledge of stratigraphy. Seismic activity increased considerably over 1950 with 924 crew months worked compared with 623 the previous year. Gravity meter also showed a marked increase with 166 crew months worked as compared with 90 last year. Production in 1951 reached an all-time high. There were 190,954,994 barrels of oil and condensate produced as compared with 167,427,924 last year. A total of 836,312,570 MCF of gas was produced as compared with 548,608,826 MCF in 1950. It is anticipated that geophysical work and leasing in 1952 will be comparable with that of 1951 and that drilling will show a slight increase.

Exploratory Drilling in 1950

This is the sixth annual report on data gathered by the committee on statistics of exploratory drilling. During 1950, 10,306 exploratory holes were drilled in the United States. Of these 5,290 were new-field wildcats, 2,495 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 2,521 were outposts. Among the new-field wildcats, 592 were successful; among the new-pool tests, 642 were successful; and among the outposts, 780 were successful. The total exploratory footage drilled in the United States in 1950 was 40,175,173 feet in the 10,306 holes, or 3,898 feet per hole. These figures compare with 34,798,291 feet drilled in 9,058 exploratory holes, with an average depth of 3,842 feet in 1949. For the third time we are presenting data on Canada and Mexico.

Exploratory Drilling in 1949

This is the fifth annual report on data gathered by the committee on statistics of exploratory drilling. During 1949, 9,058 exploratory holes were drilled in the United States. Of these 4,449 were new-field wildcats, 2,457 were new-pool tests (including new-pool wildcats, deeper-pool tests, and shallower-pool tests), and 2,152 were outposts. Among the new-field wildcats, 506 were successful; among the new-pool tests, 656 were successful; and among the outposts, 668 were successful. The total exploratory footage drilled in the United States in 1949 was 34,798,291 feet in the 9,058 holes, or 3,842 feet per hole. These figures compare with 32,741,097 feet drilled in 8,013 exploratory holes, with an average depth of 4,086 feet in 1948. For the second time we are presenting data on Canada and Mexico.

Developments in Louisiana Gulf Coast in 1949

In 1949, 956 wells were drilled in the Louisiana Gulf Coast. Of this number, 261 or 27.3 per cent were classified as exploratory wells and 695 or 72.7 per cent as field development wells. The number of exploratory wells more than doubled those in 1948. Of the 261 exploratory wells, 93 or 35.2 per cent were successful. The number of exploratory wells with their success percentage follows: new-field wildcats 133--26.3 per cent successful; new-pool wildcats 28--50.0 per cent successful; shallow-pool tests 2--50 per cent successful; deeper-pool tests 10--20 per cent successful; outposts 88--46.5 per cent successful. Of the 695 development wells, 528 or 76 per cent were successful and 167 were failures. There was a 19.0 per cent increase in number of wells drilled in 1949 with 956 as compared with 803 in 1948. These figures include only new holes drilled and do not include work-overs in shallower sands. The 35 new-field discoveries include 18 oil fields, 11 condensate fields, and 6 gas fields. Of this number, 13 were completed off shore. Thirty-two of the new-field discoveries were credited to the seismograph, two to subsurface and seismograph, and one unknown. There were several dry holes which added knowledge of stratigraphy. Seismograph operations decreased considerably during the last half of the year with only 2,537 crew weeks reported for the year. Leasing decreased approximately 50 per cent from 1948 with about 1,527,292 acres taken. The most active area was along the Miocene trend. Drilling declined considerably during the summer but became active again during the fall months.