Deeper-pool Discoveries Research Articles

Oil and Gas Developments in East-Central States in 1983

In Tennessee, 822 drilling permits were approved in 1983, 23% less than in 1982. Most permits identified the oolitic zones in the Mississippian Monteagle formation or Mississippian Fort Payne reef zones as the target. Permits in Clay County were targeted for Ordovician rocks; in Overton County, for Ordovician and Mississippian rocks. Sufficient data were received to report 992 well completions, an increase of 250% from 1982. Of these, 666 were exploratory wells and 326 were development wells. Exploratory wells were 62% successful, resulting in 138 oil wells and 273 gas wells. Development wells were 78% successful, resulting in 114 oil wells and 141 gas wells. Permit applications in the first half of 1984 indicate a slight decline in drilling. Production in Tennessee in 983 was 1,052,634 bbl of oil, about 10% less than in 1982, and 4 bcf of gas, about 34% more than in 1982. In Illinois, 2,668 oil and gas tests were processed in 1983, 9.6% less than in 1982. These included 640 exploratory wells (down 1.2%) and 2,028 development wells (down 13.9%). Exploratory wells were 13.3% successful; development wells were 68.6% successful. Exploratory successes included 11 new-field discoveries and 10 deeper pool discoveries. The most significant new-field discovery was Brooklyn field in Schuyler County, a Hunton Limestone Megagroup (Devonian and Silurian carbonates) producer. Initial potentials averaged 70 BOPD for the 28 wells reported. Discovery of a Carper sand extension to St. James field in Fayette County led to the drilling of more than 70 Carper producers in the area. A ½-mi extension discovery to Decatur field, a small 30-yr old Silurian field, led to t e completion of 5 producers that had initial potentials from 100 to 200 BOPD. The largest well in 1983 was a 720-BOPD Aux Vases well in Raleigh South field, Saline County. Thirteen additional Aux Vases (Mississippian) wells were completed. Sixty-eight wells, mostly Ste. Genevieve (Mississippian) producers, were completed in Albion Consolidated field, Edwards County. The deepest test reported in 1983, a 6,445-ft Potosi Dolomite (Cambrian) test in Washington County, was dry. Drilling activity in Illinois in 1984 is expected to remain high. Exploration for deeper production in existing fields, mostly Valmeyeran (Mississippian) and Devonian, will continue. Crude oil production in Illinois in 1983 was 29.2 million bbl, up 5.4%. In Indiana, 1,032 holes (455 exploratory, 540 development, and 37 service wells) were drilled by the oil industry in 1983, only 23 less than in 1982. Exploratory wells were 19.1% successful (82 oil, 5 gas). Development wells were 65.9% successful (338 oil, 18 gas). Older Valmeyeran rocks of the Mississippian section (Salem Limestone, Harrodsburg Limestone, and Muldraugh Formation) assumed a more significant role in exploration than in recent years. Warrick County, which had been sparsely explored because it was considered to have little hydrocarbon potential, provided cause for optimism in 1983. Folsomville field in Warrick County had produced only from the Ste. Genevieve and Harrodsburg, but in 1983, production was discovered in the Renault Formation and in additional productive area in the Ste. Genevieve and Harrodsburg. During 1983, the field produced nearly double the amount that it had produced since its discovery in 1978. The Trenton fields in east-central Indiana witnessed a surprising amount of activity in 1983, but because of disappointing recoveries, drilling there probably will decline in 1984. No major decline in drilling activity in Indiana in 1984 is anticipated. Indiana produced 5,319,578 bbl of oil in 1983, 243,118 bbl less than in 1982. In Kentucky, 6,779 permits were issued in 1983, an increase of 3% from 1982. Reported completions totalled 2,771, which were 406 fewer than in 1982. The success rate was 43.2% with 1,196 producers, 1,585 less than in 1982. There were 870 exploratory tests, with a success rate of 20.6%. Discoveries included 21 oil pools, 3 gas pools, 20 deeper oil pools, 4 deeper gas pools, 4 shallower oil pools, 2 shallower gas pools, and 125 extensions to pools. The Knox (Ordovician) play in south-central Kentucky continued to dominate drilling activity. Oil production in that area, however, declined slightly. An increase in drilling activity in Muhlenberg and Warren Counties resulted in fair success in Muhlenberg County and limited success in Warren County.

Oil and Gas Developments in New York in 1982

In 1982, 533 wells were completed in New York. In existing fields, 57 oil and 426 gas wells were completed. Exploratory drilling resulted in 4 new gas field discoveries, 1 deeper pool discovery, and 32 extensions to existing gas fields. Thirty of the extensions were to Medina sandstone fields in western New York. Pennzoil completed 2 Oriskany Sandstone gas discoveries in southeastern Cattaraugus County. Berea Oil & Gas drilled a dry downdip Medina sandstone test in the same general area. In Cayuga County, Devonian Energy drilled 3 dry Queenston tests and 1 dry Precambrian test. In Chautauqua County, 35 producers have been drilled in the northeast-southwest Akron (Bass Islands) trend. High levels of oil and gas production have occurred from fractured zones along this thrust-faulted anticlinal feature. Open flows of more than 2,400 BOPD and 60 MMCFGD have been reported. Two Devonian black shale gas tests were drilled in central-southern New York by the New York State Energy Research and Development Authority (NYSERDA). One, in Chemung County, was completed as a good gas producer, but the other, in Tioga County, was only a small producer. NYSERDA also drilled a geothermal test in the city of Auburn in central New York. The well was drilled to the Precambrian and is being tested for the production of saline formation water at 125°F for possible use in space heating. Oil production in 1982 was 831,491 bbl; gas production amounted to 18,760 mmcf. The price for New York stripper crude was $35/bbl on January 1, 1982, and ended the year at $30/bbl. In 1982, an estimated 24 crew-weeks of reflection seismic work was done in New York. Federal Energy Regulatory Commission (FERC) Section 107, tight formation, designation for the Medina in Chautauqua and Cattaraugus Counties was approved in January 1982. An application for Section 107 pricing for the Medina and Queenston in 10 additional New York counties was near approval at year end. Gas purchasers initiated extensive shut-in periods during 1982 because of the oversupply of gas. Contract renegotiations for a lower price for Section 107 gas were common. Because of this, a decline in drilling is expected in 1983. In early 1982, the U.S. Corps of Engineers gave final approval to drilling for gas in the eastern United States portion of Lake Erie. The New York portion consists of 373,000 acres. Columbia Gas has leased and done seismic work on extensive acreage in eastern New York and Vermont in the concealed eastern overthrust trend. It may drill a deep test on this acreage, near Albany, in 1983.

Oil and Gas Developments in East-Central States in 1981

In Tennessee, 316 oil and gas tests were reported in 1981, down 11% from 1980. Exploratory tests (188) were down 4.2%, and development tests were down 21.1%. In 1981, 1,228 oil and gas permits were issued, up 32.5% from 1980. Total footage drilled for the wells reported was 529,034 ft. Carbonates of Mississippian age continued to be the most important exploratory objectives. In Hancock County, a Cambrian test to a proposed depth of 17,000 ft was spudded in December. A proposed 10,500-ft test to the Precambrian is being drilled in Anderson County. Leasing was very active in 1981. Crude oil production in 1981 was 917,524 bbl, up 23.5%. Marketed natural gas was 1,718,915 mcf, up 37.7%. Nearly all of Tennessee's oil and gas production is from stratigraphic traps in the Fort P yne (Lower Mississippian) and Monteagle (Upper Mississippian) limestones. Illinois reported 3,140 exploratory and development oil and gas tests in 1981, up 58.4% from 1980. Exploratory tests numbered 665, up 47.5%. Total footage drilled, including service wells and structure tests, was 8,803,668 ft, up 61.6%. The Salem Limestone and to a lesser extent the immediately underlying Ullin Limestone (both Valmeyeran) continue to be important drilling objectives. In 1981, Salem production was discovered in 10 fields and Ullin production in 5, all deeper pool discoveries. A total of 318 Salem wells, including 61 multiple pay producers, was reported in 45 fields in 1981. Including only holes of 4,000 ft or deeper, 16 new-field and 21 new-pool exploratory wells tested the Devonian or deeper. At total depth, 1 of these tested the St. Peter, 5 tested the Trenton, and 31 tested Devonian-Silurian rocks. Only 2 of the wells--both Devonian deeper pool discoveries--were exploratory successes. The deepest well reported in 1981 was a 6,105-ft test in Franklin County. It was completed as a deeper pay discovery in the Devonian. Crude oil production in 1981 was 25,490,000 bbl, up 10.2% from 1980. Indiana reported 811 oil and gas tests in 1981, an increase of 11.9% over 1980; 348 exploratory tests were drilled (up 8.1% from 1980), with a success rate of 20.1%. Drilling for oil in a sandstone of the Renault Formation (Mississippian), spurred by successes in Posey County in 1980, resulted in 7 exploratory successes in the Renault sandstone in Posey and Gibson Counties in 1981. In Miami County, northern Indiana, in an area of the Peru field that data suggested was untested, a successful Trenton Limestone well was completed in 1981. The field was discovered in 1895. Testing and leasing in the main area of the old Trenton field in east-central Indiana continued in 1981. Estimated crude oil production in Indiana in 1981 was 4,730,000 bbl, down about 248,000 bbl from 1980. In Kentucky, 5,364 permits were issued in 1981, an increase of 29.8% over 1980. The number of oil and gas tests completed was 1,679, an increase of 35%. Of these, 852 were producers, an increase of 47%. Of the 486 exploratory wells drilled, 124 were successful, a success rate of 25.5%. Discoveries included 3 oil fields, 4 gas fields, 15 deeper oil pools, 1 deeper gas pool, and 1 deeper combination oil and gas pool. Continued interest in deep Cambro-Ordovician strata in the Rome trough throughout central and eastern Kentucky, heightened by some successes, should ultimately lead to the discovery of sizable reserves. Estimated oil production in 1981 was 6,540,484 bbl, an increase of 10%. Gas production was 61.3 bcf, an increase of 5.2%.

Oil and Gas Developments in New York in 1981:

In 1981, there were 646 wells completed in New York. This figure is partly estimated. In existing fields, 107 oil and 450 gas wells were completed. The results of exploratory drilling included 12 new gas field discoveries, 4 new gas pool discoveries, 3 deeper pool discoveries, 1 shallower pool discovery, and 36 extensions to existing gas fields. Two Medina Sandstone discoveries were made in Allegany County. Nine Devonian black shale wells were completed in western New York. An Onondaga reef discovery was made in Cattaraugus County. Three Trenton Limestone discoveries were made in central New York. Arco completed a dry hole in eastern New York near the Eastern Overthrust area. A significant oil discovery from the Bass Islands zone below the Onondaga Limestone was made in eastern Chautauqua County. Thirty-five extensions to Medina Sandstone gas fields were completed in 1981. There was also 1 extension to the Houghton, Marcellus black shale gas field. In all, 8 Devonian black shale discoveries, 8 Silurian Medina Sandstone discoveries, and 3 Ordovician Trenton Limestone discoveries were made in New York during 1981. Oil production in 1981 was 848,969 bbl and gas production amounted to 19,000 mmcf. The price for New York stripper crude was $38.00/bbl on January 1, 1981, and ended the year at $35.00/bbl. Wellhead gas prices ranged up to $3.18/mcf. In 1981, 6 companies accomplished 49 crew-weeks of reflection seismic work in New York. A portion of a state park was leased by competitive bidding. Leasing continued in the Eastern Overthrust area of eastern New York and in central and western New York. An amended oil and gas law was passed. One of the main effects will be to substantially increase fees for drilling permits. FERC Section 107, Tight Sands, recommendations for 2 separate applications involving the Medina and Queenston formations in 12 New York counties are pending and approval is expected in 1982. Drilling for Medina Sandstone gas production and Devonian black shale gas production will continue. However, it is expected that overall drilling will decline due to a softening in crude oil prices and an oversupply of gas. Federal government approval of leasing and drilling for gas in Lake Erie has still not been forthcoming.

Geology and Geophysics of Middle Mississippian (Valmeyeran), Ewing Area, Jefferson and Franklin Counties, Illinois: ABSTRACT

Since 1976, significant new oil reserves have been discovered in the Ewing area of Jefferson and Franklin Counties, Illinois. One new field and three deeper pool discoveries contain oil reserves in excess of 1.2 million bbl. These oil reserves are in Middle Mississippian limestone at depths of less than 4,000 ft (1,219 m). Spring Garden field, discovered in November 1977, was drilled on a seismic prospect and has 600 acres (240 ha.) under production from the McClosky Limestone Member of the Ste. Genevieve formation. A study of a core from the field indicates the reservoir was deposited in an oolite bar or beach environment similar to present-day deposition at the Lily Bank oolitic shoal in the Bahamas. The trap at Spring Garden field is formed by the updip pinch-out of porous oolitic limestone into a tight micritic lime mud on a structural nose. The field has primary recoverable reserves of 600,000 bbl of oil. Based on seismic work and well control, deep tests were drilled in three old fields: Bessie, Ewing East, and End_Page 1281------------------------------ Taylor Hill. All three fields had previously produced oil from the O'Hara Limestone Member of the Ste. Genevieve formation. New production has been established in the three fields from the deeper Salem and Warsaw limestone section. Oil in all three fields is found in a combination of structural and stratigraphic traps. New reserves in Ewing East and Taylor Hill total about 400,000 bbl of oil. The Bessie field is currently in the development stage but preliminary indications show the reserves should greatly exceed those of Taylor Hill and Ewing East. Recent geophysical work in the Ewing area, employing a portable mini-hole seismic crew, indicates several more untested features which occur along the same Middle Mississippian depositional trend that created the producing facies in the above fields. The new portable mini-hole seismic operation has made it possible to survey areas previously unaccessible by deep hole or vibroseis crews. End_of_Article - Last_Page 1282------------

Developments in New York in 1979

In 1979, an estimated 623 wells were completed in New York. In existing fields, 172 oil and 370 gas wells were completed. Exploratory drilling resulted in 12 new gas-field discoveries, 1 deeper pool gas discovery, and 27 extensions to existing gas fields. Two discoveries were in the Lower Devonian Oriskany Sandstone, one along the Oriskany pinch-out and the other on a structure. One discovery in the far western part of the state found gas in the Silurian Medina Sandstone and also in the shallow Upper Devonian Glade sandstone. The deeper pool discovery is in the Medina Sandstone in the shallow Busti oil field. All of the remaining discoveries and extensions were in the Medina Sandstone in western New York. Three dry Cambrian-Precambrian tests were drilled in the western part of the state. Oil production in 1979 was 854,604 bbl and gas production amounted to 15,500 MMcf. The price for New York stripper crude increased substantially during 1979, rising from $14.77/bbl to $38.00/bbl on 1/1/80. Gas prices ranged up to $2.17/Mcf. During 1979, 6 companies accomplished 70 crew-weeks of reflection seismic work in New York. Leasing continued in areas of possible Medina and Queenston gas production in western and central New York. Columbia Gas Project Penny will stimulate drilling for Medina gas production in western New York. A successful Devonian black shale gas test was drilled in 1979 and will be completed in 1980. Several additional Devonian black shale tests are planned. Several exploratory wells are planned for central New York. Leasing and drilling in the New York part of Lake Erie are still delayed until completion of a federal environmental impact study.

Developments in New York in 1978.

In 1978, 482 wells were completed in New York. In known oil and gas fields, 161 oil and 195 gas wells were completed. Gas well completions were down 20% from 1977 because of a lack of pipeline capacity in the far southwestern part of the state. Exploratory drilling resulted in 13 new gas-field discoveries, 1 deeper pool gas discovery, and 15 extensions to known gas fields. All the discoveries are in the Silurian Medina Sandstone in the western part of the state. The deeper pool discovery is in the Devonian Oriskany Sandstone in western New York. One extension was to an Ordovician Queenston field in central New York and the rest were extensions to Medina fields in the western part of the state. In a dry Medina test in Allegany County, a 1,652-ft Devonian black shale core was cut. In eastern New York, Gulf drilled a deep wildcat which was dry. Oil production in 1978 was 852,462 bbl and gas production amounted to 13,000 MMcf. The price for New York stripper crude held steady at $14.77/bbl during 1978. Gas prices varied up to $2.25/Mcf. During 1978, 70 crew-weeks of reflection seismograph work and 18 crew-weeks of gravity work were accomplished in New York. Leasing continued in areas of possible Medina and Queenston gas production in western and central New York; 7 state reforestation tracts totaling 12,274 acres were leased at an average price of $7.15/acre during 1978. Exploration and development in Medina and Queenston gas-producing areas will continue. A few deep tests as well as Devonian black shale and Oriskany structural tests will be drilled in 1979. Leasing and drilling in the New York part of Lake Erie are delayed until completion of an environmental impact study.

Petroleum Exploration and Production in Europe in 1977

North Sea oil production rose to 1,242,000 b/d in December 1977, although production from several large fields was curtailed. Onshore oil production in western and southern Europe declined slightly in Austria, France, and Germany, and increased modestly in the Netherlands, Britain, and Yugoslavia. Overall gas production increased slightly, but there were declines in Italy and the Netherlands. The giant Frigg and Ekofisk North Sea gas fields went on production through pipelines to shore terminals. A Jurassic discovery in the central North Sea, Fulmar, was confirmed as an important field. Oil was tested in 3 wells in the West Shetland basin, and at least 1 of these may be a commercial discovery. Drilling extended into previously undrilled basins west and east of Ireland, in luding 2 wells at water depths below 1,500 ft (470 m). An important deeper pool discovery was reported in the Wytch Farm field onshore in southern England. Two offshore oil discoveries, both in water 2,200 ft (680 m) deep, were made off the east coast of Spain. In Italy, an interesting stratigraphic trap gas discovery was made in the Po basin, and an oil find was made offshore west of Sicily. Small gas and oil discoveries were made onshore in Austria, Germany, the Netherlands, and Yugoslavia. In the Soviet Union, average daily production of crude oil and condensate was 10,920,000 bbl and of gas 33.8 Bcf. The Samotler field in the West Siberian basin accounted for 2,600,000 b/d of the total oil, and efforts were intensified to find new reserves to offset the eventual decline of that field. Major gas pipelines were under construction to open the large gas fields of the Arctic part of the West Siberian basin.

Petroleum Developments in Australia in 1975

Exploration and development activity in Australia declined in 1975 relative to 1974. Exploration footage drilled in 1975 was about 60% less than in 1974. Only 20 wildcats were drilled in 1975; most of these were on the northwest shelf. One successful wildcat and 1 deeper pool discovery were made in that area. Elsewhere wildcats were unsuccessful, both onshore and offshore. Onshore development work resulted in 4 successful gas wells in the Cooper basin, South Australia.

Developments in West Coast Area in 1974

Exploratory activity in Washington declined. Four wells were drilled in the Grays Harbor area; none was successful. The only exploratory activity in Oregon was some leasing in the Coast Range south of Eugene. A deeper pool discovery at the Tule Elk field was the only significant new discovery in California. Several small gas discoveries were made in the Sacramento Valley. Development drilling in California nearly doubled the 1973 rate. Seismic activity increased onshore in the Sacramento and northern San Joaquin Valley and offshore south of the Santa Barbara Channel Islands where an OCS lease sale is expected in 1975.

Developments in East-Central States in 1974

Total oil production in Illinois, Indiana, Kentucky, and Tennessee in 1974 was 41 million bbl, down 8.9% from 1973. Tennessee had a 275% increase; all the other states had decreases. Gas production in Kentucky was 69.7 Bcf, about the same as in 1973. Gas production in the other states is not significant. A total of 1,964 oil and gas tests was drilled in 1974, up 28.9% from 1973. Exploratory tests totaled 658, up 16.5%; of these, 125 (19%) were successful. Tennessee had 135 oil and gas tests in 1974, up 37.7% from 1973. Exploratory tests were up 28.8%. Total footage drilled was 214,877, of which 140,343 ft was exploratory. Most of the drilling was in Morgan, Scott, and Fentress Counties, where the primary objective was the Lower Mississippian Ft. Payne carbonate rock. Successful exploratory wells in 1974 included 10 new fields, 4 new-pool wildcat discoveries, 1 deeper pool discovery, and 13 extensions. Indian Creek field in Morgan County was the most significant discovery in 1974. Almost all production from this field is from the Ft. Payne; primary reserves are estimated at more than 1 million bbl. Two deep tests, a 6,334-ft basement test in DeKalb County, and a 3,995-ft test in the Copper Ridge Dolomite in Smith County, were drilled in 1974; both were unsuccessful. Several majors reportedly are leasing large blocks in eastern Tennessee. Leasing also continued in the area of Morgan, Scott, and Fentress Counties. Crude oil production in Tennessee in 1974 was 768,700 bbl, up from 205,000 bbl in 1973. Illinois had 795 oil and gas tests in 1974, up 43% from 1973. Exploratory tests were up 12.8%. Total footage drilled in oil and gas tests and service wells was 2,023,761, up 39.9%. Six new fields, 16 extensions, 3 new-pool wildcats, 5 deeper oil pools, and 2 shallower oil pools were discovered. None of the discoveries adds significantly to reserves. About 75% of the 103 new-field wildcat tests drilled were on the shelf area west and northwest of the deep Fairfield basin. Sixty-five of the new-field wildcats tested Devonian or deeper strata. One of the outstanding features of 1974 activity was the large number of wells testing the Mississippian Ullin Limestone (Valmeyeran). For example, Clay City Consolidated field, which had only 3 Ullin producers at the end of 1973, had 43 Ullin test in 1974, of which 14 were completed in the Ullin. Indications are strong that several deep tests will be drilled in Illinois in 1975, with Trenton and deeper strata as their objective. Activity south of the Rough Creek lineament is expected to increase in 1975. Crude oil production in Illinois in 1974 was 27,554,000 bbl, a decline of 10.2%. Indiana had 376 exploratory and development tests in 1974, up 57.3% from 1973. Twenty-nine more exploratory wells were drilled in 1974 than in 1973. Successful exploratory percentage increased from 10.1% in 1973 to 14.1% in 1974. With a few exceptions, all of the drilling activity in 1974 was in the Illinois basin part of Indiana. Exploratory successes included 7 new fields, 14 new pools, and 3 extensions. Three of the 1974 discoveries were on structures that exhibit anomalies which suggest buried Silurian reefs. Sizable undrilled blocks exist in the areas of expectable reefs, and continued testing of these areas is assured. Because of higher crude prices, many old fields which had become uneconomic probably will receive remedial action. Some attempts at tertiary recovery also are ant cipated. Estimated crude oil production in 1974 is 4,950,000 bbl, a decline of 6.8%. A total of 658 oil and gas tests was drilled in Kentucky in 1974, up 4.3% from 1973. Of 184 exploratory tests drilled, 44 (23.9%) were successful. The exploratory successes included 7 fields, 25 extensions, 4 deeper pools, and 8 shallower pools. A Cambrian test in Stephens field, Elliott County, was drilled to TD 9,473 ft and completed as a 500 Mcf gas producer in the Ordovician Wells Creek Formation at 4,875 ft. Among unsuccessful deep exploratory tests in 1974 were a Precambrian test drilled to TD 13,035 ft in Big Sandy field, Floyd County; 2 Knox tests a little more than TD 6,000 ft, 1 in Breckinridge County and 1 in Johnson County; and a 7,608-ft Antietam test in Morgan County. The last 3 wells are new-field wildcats. At year-end a scheduled Cambrian test was drilling in Webster C unty, and Texas Gas was scheduled to complete a Grayson County test to a depth in excess of 13,000 ft.

Petroleum Developments in Australia and Oceania in 1973

Petroleum exploration activity decreased by 40 to 50 percent in Australia during 1973 relative to 1972. The decrease is attributed to several political and economic factors believed to be unfavorable to the oil and gas industry. Sixty-seven exploration wells and 16 development wells were drilled or drilling in Australia during 1973. About half of the exploration wells were drilled offshore. Offshore, the principal active areas remained the Gippsland basin of Victoria and the northwest shelf of Western Australia. Onshore, there was little significant drilling activity with exception of the Cooper basin of northeast South Australia and southwest Queensland. In this basin there were only 3 exploration tests drilled, but all were gas discoveries. In 1973 Australian oil production was 22,443,266 cu m (141,168,140 bbl) and gas production was 4,343,102,000 cu m (153,832,670,000 cu ft). At mid-1973 Australia's reserves were about 4.5 billion bbl of oil and natural gas liquids and 38 Tcf of gas. Three new-field discoveries and 1 deeper pool discovery on the northwest shelf, together with successful delineation wells on 3 new fields in the Gippsland basin should increase the total reserve. In Papua-New Guinea 2 new areas of exploration drilling not tested previously included the Sepik basin of northern New Guinea and southeast of Papua in the offshore part of the Vogel basin. Geophysical exploration was the principal activity in several parts of Oceania during 1973. Fiji appears to have been the site of greatest activity in this region.

Oil and Gas Developments in North Carolina, Maryland, Virginia, Pennsylvania, West Virginia, and Ohio

The area covered by this report is CSD District 20, including Delaware, North Carolina, Maryland, Virginia, Pennsylvania, West Virginia, and Ohio. Along the Atlantic coastal plain in North Carolina, 5 dry exploratory holes were drilled having a combined total footage of 6,785. In Maryland, 1 dry exploratory hole was drilled to the Oriskany Formation in Garrett County to a total depth of 5,340 ft. In Virginia, only a few of the 12 wells drilled in Chesterfield, Lee, and Tazewell Counties were completed as producers. Most of the gas production for the year came from Tazewell County, whereas the oil production was all in Lee County. The total footage drilled in Virginia was 22,069. Exploration in Pennsylvania resulted in 1 new shallow-field discovery, 3 new shallower pool discoveries, and 1 new deeper pool discovery. The greatest amount of Oriskany Sandstone development drilling was in the Elk Run gas field in western central Pennsylvania, whereas the most active deep drilling was in Erie and Crawford Counties (northwestern Pennsylvania) where development drilling continued in the Lower Silurian gas fields. Developments continued in the old shallow sandstone oil and gas areas of Warren and Venango Counties, as did waterflooding in the Bradford district, McKean County, and the continuation of development drilling in the Run gas field of Jefferson, Indiana, and Clearfield Counties. There were 5 major areas of interest in West Virginia: southern Monongalia County where 6 successful gas wells were completed in South Burns Chapel field in the Onondaga-Oriskany interval; the Kanawha-Putnam Counties area where Rocky Fort field underwent rapid development in the Newburg sand (Upper Silurian); northern Kanawha County where several wells were drilled for Injun oil (middle Mississippian); Nicholas County where a new gas field was being developed in the Big Lime (middle Mississippian Greenbrier Limestone); and in Roane County where 94 Injun oil wells were completed. Drilling activity in Ohio was directed toward the Cambrian in central Ohio, and the Silurian Clinton sandstones and the Lower Mississippian Berea Sandstone in southeastern Ohio. Early in 1967 a plug-back operation in a Precambrian test drilled in 1966 discovered oil in the Devonian Ohio Shale section in southeastern Ohio. Discovery of oil from the Ordovician Trenton Limestone-Dolomite in the north-central part of the state created a minor flurry of excitement.

Railroad Gap Area--New Reserves in Old Province: ABSTRACT

The Railroad Gap area, consisting of the Railroad Gap field and the deeper pools at Northeast McKittrick and McKittrick Front, is on the west side of the San Joaquin Valley near McKittrick, Kern County, California. The discovery of the Railroad Gap field in February, 1964, by the Standard Oil Company of California led to the deeper-pool discoveries at Northeast McKittrick and McKittrick Front by the same operator during the ensuing 1½ years. Anticlinal closure traps most of the reserves in each field. The folds differ considerably in size, configuration, and orientation. Normal and reverse faults are common, and cause differences in oil-water interfaces within the same accumulation. Nearly all stratigraphic units from the Eocent Point of Rocks Sandstone Member to the Pleistocene Tulare Formation are productive in the area. The primary objectives and most prolific reservoir rocks are the Oligocene Oceanic and the lower Miocene Phacoides and Carneros Sands. The massive Phacoides and Oceanic Sand units differ considerably in thickness and reservoir quality from place to place. The Phacoides permeability variations are particularly surprising, because initial completions range from 100 to 9,000 BOPD at similar structural positions within the same accumulation. The Railroad Gap area was known to be anticlinal, but conclusive evidence of critical closure on the northwest could not be documented by conventional structural studies or geophysical methods. Regional isopachous studies of the middle and upper Miocene, however, indicated the existence of thickness variations of a sufficient magnitude that potential northwesterly closure could be inferred to be present in the underlying lower Miocene sediments. The isopachous contours reflect middle and late Miocene structural growth along the trend, suggesting a favorable geologic history for the area. The lower Miocene and Oligocene, from nearby well data, were known to contain excellent clastic reservoirs, thus completing the knowledge necessary to justify an exploration program. End_of_Article - Last_Page 486------------

Developments in Northern Rockies in 1965

In general, 1965 was a good year in the Northern Rockies. In Wyoming, overall drilling of 948 tests was down compared with previous years, but 32 new-field discoveries were made, 2 of which were of unusual significance because of their depth and apparent establishment of large reserves. Montana had its most active year to date with a total of 504 tests. Ten new fields, 6 pool discoveries, and 2 extensions resulted. Activity in South Dakota, while showing a significant statistical increase over recent years, was still nominal with only 31 tests having been drilled. In North Dakota, 240 wells were drilled, compared with 277 in 1964. One new-field wildcat, 3 extension wells, and 2 deeper-pool discoveries were drilled.

Developments in North Mid-continent in 1961

During 1961, there were 4,401 wells drilled for oil or gas in Kansas. Excluding the shallow stripper area of southeastern Kansas, the total drops to 3,276. Of this latter figure, 49% were successful. Production in Kansas for 1961 amounted to 112,210,936 bbls. of oil, 6,150,086 bbls. of LPG and natural gasoline, and 676,235,505 MCF of natural gas. Exploratory tests in Kansas during 1961 numbered 1,165 and included 103 oil discoveries, 33 gas discoveries, 68 extensions to oil pools, 28 extensions to gas pools, and 933 dry holes. New-field, new-pool, and outpost discoveries numbered 115. There were 20 deeper-pool discoveries and 1 shallower-pool discovery during 1961. Available information indicates that 20 exploratory tests were drilled during 1961 in Iowa, Missouri, and that part of Nebraska east of the 98th Meridian. None of these 20 tests was successful.

Developments in North Mid-Continent in 1960

During 1960, there were 4,187 wells drilled for oil or gas in Kansas. Of this number, 54.6% were successful. Production in Kansas for 1960 amounted to 113,344,548 bbls. of oil, 4,862,277 bbls. of natural gasoline and LPG, and 632,609,850 MCF of natural gas. Exploratory tests in Kansas during 1960 numbered 1,104, including 97 oil discoveries, 21 gas discoveries, 75 extensions to oil pools, 22 extensions to gas pools, and 889 dry holes. New-field, new-pool, and outpost discoveries numbered 107 during 1960; this figure includes 7 discoveries which resulted from old holes worked over. There were 17 deeper-pool discoveries and 1 shallower-pool discovery during 1960. Available information indicates that 22 exploratory tests were drilled during 1960 in Iowa, Missouri, and that part of Nebraska east of the 98th Meridian. None of these 22 tests was successful.

Developments in Wyoming and Idaho in 1954

There were 269 exploratory wells drilled in Wyoming in 1954 as compared with 260 in 1953. New-field wildcats numbered 190, a 30% increase over the 146 drilled in 1953. Total exploratory tests were 21.9% successful and new-field wildcats found 16 new oil fields and 5 new gas fields, making an 11% success ratio. Total footage drilled rose 15.3% to 1,462,944 feet and average depth per test well increased to 5,438 feet. Development drilling increased 32% and oil production reached an all-time high of 89,083,000 barrels. Five new-field discoveries and 6 new-pool--deeper-pool discoveries seem particularly significant. The 1954 discoveries will direct exploratory drilling to a wider part of the state's area during 1955.

Developments in Michigan in 1954

In Michigan during 1954 exploratory and development drilling again registered a small decline compared with the 1953 figures. There were 253 exploratory completions this year against 283 exploratory completions in 1953. The development-well completions total of 312 was 20 completions less than the 1953 figure of 332. Of the 253 exploratory wells: 231 were dry and 22 were successful, resulting in 10 new-field discoveries, 1 new-pool discovery, 5 deeper-pool discoveries, and 6 new extensions. The major concentration of development and exploratory effort continues to be directed toward the finding and developing of new reserves in the Central Basin and the Southwestern areas of Michigan. Southeastern Michigan continues to be the scene of considerable exploratory and development effort with the Trenton and Niagara formations as the objectives. Total footage drilled in 1954 was 1,511,906 feet compared with the 1953 total drilled footage figure of 1,785,256 feet. Oil production in Michigan showed a small decline: 12,028,059 barrels were produced compared with 12,284,510 barrels produced in 1953. The average daily production for Michigan in 1954 was 32,954 barrels or about ½ per cent of the daily national total. Gas production showed a considerable decline, with 5,698,175 MCF being produced compared with 7,084,616 MCF in 1953. Core-drill work showed a slight rise, with 80 permits issued in 1954, compared with 47 permits in 1953. These figures are comparable with 556 permits issued in 1951, a peak year for core-drill activity. Geophysical work was limited to the gravity meter, no seismograph work being reported during the year. Eight different companies engaged in gravity-meter work, covering parts of Southeast, Southwestern, and Western Michigan. Subsurface geology continues to be the most successful exploration method used in Michigan. In 1954 unsuccessful new-field wildcats numbered 180; of these, 170 were located on subsurface geology, 8 on gravity meter, 1 reported to be located on seismic information, and 1 on non-technical information. The lease inventories of 14 major and independent oil companies operating in Michigan showed 1,348,937 undeveloped acres under lease on December 31, 1954, a 31.8 per cent drop compared with the 1,977,688 undeveloped acres under lease by the same 14 companies, December 31, 1953.

Developments in Michigan in 1953

In Michigan during 1953 both exploratory and development drilling registered a small decline compared with the 1952 figures. There were 283 exploratory completions this year against 293 exploratory completions in 1952. The development well completions total of 332 in 1953 was 10 less than the 342 total in 1952. Of the 283 exploratory wells drilled, 257 were dry and 26 were successful, resulting in 13 new-field discoveries, of which 9 were oil discoveries and 4 were gas discoveries. Developments since the end of the year indicate that none of the oil-field discoveries has added substantially to the Michigan oil reserves. Further drilling will prove the importance of the gas discoveries as to added gas reserves. The pool discoveries are 7 in number; 5 are classified as new- ool discoveries and 2 are deeper-pool discoveries. Of the seven pool discoveries, 5 were completed in the Richfield zone of the Detroit River formation (Devonian). There were 6 successful outpost wells for the most part making extensions to the shallow Traverse limestone fields in southwestern Michigan with no important addition of reserves indicated. A field well, not included in exploratory figures, found a new pay in the sour zone of the Detroit River formation in Clare County. Total footage drilled in 1952 was 1,785,256, which is approximately 2.3 per cent under the 1952 figure of 1,828,531 feet. Oil production in Michigan continued to decline; 12,284,510 barrels were produced in 1953 compared with 13,251,464 barrels in 1952, a decline of 7.3 per cent. Gas production likewise declined; 7,084,616 MCF were produced, compared with 8,677,737 MCF in 1952. Core-drill work hit a new low with only 47 permits compared with 223 permits issued in 1952. In line with the trend to the use of more geophysics, the gravity meter continued its popularity as the principal geophysical instrument in use. Seismograph work, though comparatively small, showed an increase. Subsurface geology continues to be the most successful exploration method used in Michigan. The major concentration of exploratory effort continues to be directed toward the finding of new reserves in the Central basin and Southwestern areas. Considerable exploratory effort continues to be concentrated in the Eastern and Southeastern areas in the search for basal Salina Niagaran production. The lease inventories of 14 major and independent oil companies operating in Michigan showed 1,977,688 undeveloped acres under lease on December 31, 1953, compared with 2,327,723 undeveloped acres under lease by the same 14 companies at the end of 1952.