Review of Kentucky Oil and Gas Production, 2010

The 2010 oil and natural gas production data by well published by the Kentucky Division of Oil and Gas were analyzed in response to proposed rules for limiting emissions from oil and natural gas facilities. Average daily production was determined for 5,044 oil wells and 12,940 natural gas wells. Of these wells, 955 are combined oil and natural gas producers. The overwhelming majority of Kentucky’s wells are marginal (stripper) wells and produce at rates of less than 10 barrels of oil (or barrels of oil equivalent) per day (bo/d) or 60 thousand cubic feet of natural gas per day (Mcf/d) during the months they are operated. The median oil production rate is 0.87 bo/d. The median natural gas production rate is 12 Mcf/d. The 2010 data used in this assessment include production for both recently completed wells and very old wells, the oldest having been completed in 1912. Although the data describe the production across the state that could contribute to emissions, the findings do not reflect newer wells that are expected to be in the early phase of production. A total of 151 oil wells and 1,468 natural gas wells were selected for study that were completed since January 1, 2005, were operated for 12 months in 2010, and had at least 36 months of production. The median oil well in this category produced 2.2 bo/d over all periods the well was operated. Production data for 2010 consisted of information for only four horizontal oil wells, not sufficient to compare the performance of horizontal and vertical completions. The median natural gas well in this category produced an average of 28 Mcf/d over all periods during which the well was operated. For these gas wells, there were 1,217 vertical and 251 horizontal completions. Horizontal natural gas wells exhibit higher maximum monthly production rates and greater 3-yr cumulative production than was observed in most conventional vertical wells

Index to Oil and Gas Fields of Kentucky

These data have been collected by the Kentucky Geological Survey as part of an ongoing project, and this report is subject to updating and revision as additional data become available. Where information is not available for a certain category, the entry is left blank. Data are listed in order by county and field name. Producing formations generally are listed in approximate stratigraphic sequence from youngest to oldest. The date shown is the year of completion of the discovery well in the field. The Carter coordinate location pertains only to the discovery well of the field and in some cases may be outside the listed county; other wells in the field may lie outside the given Carter coordinates. Kentucky is divided into four regions (Fig. 1) as defined by the American Association of Petroleum Geologists (Meyer, 1968). Tables 1, 2, and 3 show producing zones for each of the three regions in Kentucky that produce oil and gas. No production has been recorded for the Mississippi Embayment region in the far western part of the State. Oil production was rumored in McCracken County, but this was never substantiated. For additional information about this listing, contact Brandon Nuttall at the Kentucky Geological Survey

The Middle and Upper Ordovician Bioclastic Carbonate ( Trenton ) Play in the Appalachian Basin

The bioclastic carbonate play in the Appalachian Basin (referred to by drillers as the Trenton ) includes both gas and oil produced from Middle and Upper Ordovician stratigraphic and combination traps in linear reservoirs often mistaken for reefs. While production from this play is currently reported from nine fields in south-central and eastern Kentucky and five fields in New York, potential reservoir rocks are present throughout most of the Appalachian Basin from New York to Tennessee. Along the western flank of the Appalachian Basin, in the Blue Grass Region of central Kentucky, Middle and Upper Ordovician strata crop out. In the subsurface of south-central Kentucky and eastward into the Appalachian Basin, drillers informally refer to Trenton, Sunnybrook, Leipers, Granville, Modoc, and Anderson pay zones. The mixed carbonates and shales of the Lexington Limestone through the Drakes Formation of Kentucky consist of well-cemented bioclastic grainstones and mudstones separated by relatively thin calcareous shales deposited in shallow platform, ramp, and peritidal settings. In areas of shoaling, reservoirs developed as discontinuous coquinoid lag deposits that were winnowed from carbonate muds by wave and tidal activity and accumulated as discrete offshore bars, tidal bars, and channel fills. In addition, dolomitized limestone reservoirs have developed along faults and fractures associated with recurrent movement of deep-seated basement faults. Structure mapping on the base of the overlying Devonian shale and the underlying Pencil Cave bentonite indicates the bars and channel fills may be spatially associated with basement structures. The Granville Consolidated Pool in Clinton Connty, Ky., is typical of fields in this play where production is associated with multiple stacked sequences of Offshore bars. An estimated 50 to 100 million cubic feet (MMcf) of gas per year is known to be produced from this field, not accounting for production from an unknown number of domestic supply wells. Monte Carlo simulation was used to estimate the undiscovered recoverable resource for this play to be 127billion cubic feet (bcf) of natural gas. These reservoirs will probably not be an important primary target for future drilling outside of southern and eastern Kentucky, however, because the reservoirs are relatively deep throughout much of the basin and are subtle stratigraphic features that will be difficult to detect using seismic or remote-sensing methods. As exploration and development continues for Lower Ordovician and Upper Cambrian reservoirs, these bioclastic carbonate bars will merit further evaluation

Middle and Late Devonian New Albany Shale in the Kentucky Geological Survey Marvin Blan No. 1 Well, Hancock County, Kentucky

A 30-ft section of core was recovered in the Grassy Creek Member of the New Albany Shale in the Kentucky Geological Survey Marvin Blan No. 1 well, Hancock County, Ky. (permit 104925, API No. 16091013960000). Analysis characterized the New Albany Shale as a regional seal for preventing vertical migration of carbon dioxide stored in deeper zones, as a natural gas reservoir, and for its potential for enhanced gas recovery and sequestration of carbon dioxide. A show of natural gas at the top of the New Albany Shale was encountered during drilling. Core was recovered in an aluminum sleeve cut into 3-ft sections. The sleeved sections were capped, sealed, and shipped to Weatherford Laboratories for analysis. An X-ray computed tomography scan of the core, a standard openhole nuclear log suite, and spectral gamma-ray data formed the basis for establishing a sampling and analysis protocol. Three 1-ft intervals were selected for archiving and were sealed in wax. The remaining core was slabbed. The quarter-section slabs were reserved for examination and archiving. The three-quarter-section slabs were photographed and sampled. The New Albany Shale in the Blan well averages 9.5 × 10–5 md permeability with a compressive strength of 13,487 psi, a static Young’s modulus of 1.58 x 106 psi, and a static Poisson’s ratio of 0.20. These properties demonstrate that the shale is an adequate seal for deeper reservoirs. Although thermal maturity is low, the shale is oil-prone, with excellent marine kerogen and bitumen contents. The methane gas content is 55.9 standard cubic feet of gas per ton of shale. This low gas content, when considered in light of low permeability, indicates the New Albany has low potential for thermogenic gas production in the area of the Blan well. Economic gas recovery would likely require horizontal drilling and advanced well-completion technologies. Adsorption isotherms indicate an estimated carbon dioxide gas content of 137.7 scf/ton at an estimated reservoir pressure of 812 psi, indicating preferential adsorption. In addition, as much as 181 tons of carbon dioxide could be sequestered per acre in the New Albany Shale (over its total thickness), suggesting a possible mechanism for enhanced natural gas recovery

CO\u3csub\u3e2\u3c/sub\u3e-Enhanced Gas Recovery in Shale: Lessons Learned in the Devonian Ohio Shale of Eastern Kentucky

The Kentucky Geological Survey tested CO2-enhanced gas recovery in the Devonian shale in Johnson County, in response to a directive from the Kentucky General Assembly in 2007; the study site included a fracture-stimulated shale-gas well. To supplement a standard suite of open-hole logs acquired when the well was drilled, a well-logging program was designed to identify open perforations, construct a flow profile, and acquire pre-injection baseline data to characterize the Devonian Ohio Shale for a pressure falloff test. Tubing and packer were installed, with gel and brine filling the annulus between the tubing and packer to block flow-through perforations identified above the packer. From Sept. 6–10, 2012, 87 tons of CO2 was injected in three phases, with at least 12 hr between phases to allow for pressure decline. On the last day of injection, the pressure of the annulus between the casing and injection tubing approached the injection pressure, indicating CO2 had leaked out of the test zone. Therefore, the test was terminated before a planned injection of 300 tons of CO2 was completed. Following injection, the well was closed for 2 weeks to allow a “soak.” A meter run was constructed to monitor flowback, and during the flowback a second flow profile and post-injection production log were acquired. Analysis indicates the leak was likely the result of communication through induced fractures (from the original completion) from the Ohio Shale to the overlying Berea Sandstone. The Ohio Shale likely retained some of the CO2, thus confirming the potential to displace additional natural gas, but the small volume of CO2 and escape of an unknown amount of CO2 from the zone of interest severely constrained anything but a qualitative assessment