Ronald R. McDowell

Heterogeneity of Fluvial-Deltaic Reservoirs in the Appalachian Basin: A Case Study from a Lower Mississippian Oil Field in Central West Virginia

Since discovery in 1924, Granny Creek field in central West Virginia has experienced several periods of renewed drilling for oil in a fluvial-deltaic sandstone in the Lower Mississippian Price Formation. Depositional and diagenetic features leading to reservoir heterogeneity include highly variable grain size, thin shale and siltstone beds, and zones containing large quantities of calcite, siderite, or quartz cement. Electrofacies defined through cluster analysis of wireline log responses corresponded approximately to facies observed in core. Three-dimensional models of porosity computed from density logs showed that zones of relatively high porosity were discontinuous across the field. The regression of core permeability on core porosity is statistically significant, and differs for each electrofacies. Zones of high permeability estimated from porosity and electrofacies tend to be discontinuous and aligned roughly north-south. Cumulative oil production varies considerably between adjacent wells, and corresponds very poorly with trends in porosity and permeability. Original oil in place, estimated for each well from reservoir thickness, porosity, water saturation, and an assumed value for drainage radius, is highly variable in the southern part of the field, which is characterized by relatively complex interfingering of electrofacies and similar variability in porosity and permeability.

Uncertainty in coal property valuation in West Virginia: A case study

AbstractInterpolated grids of coal bed thickness are being considered for use in a proposed method for taxation of coal in the state of West Virginia (United States). To assess the origin and magnitude of possible inaccuracies in calculated coal tonnage, we used conditional simulation to generate equiprobable realizations of net coal thickness for two coals on a 7

Tracing Fossil History

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Evidence of basement-block movement, middle Ordovician shelf sediments, western passive margin, North America

min topographic quadrangle, and a third coal in a second quadrangle. Coals differed in average thickness and proportion of original coal that had been removed by erosion; all three coals crop out in the study area. Coal tonnage was calculated for each realization and for each interpolated grid for actual and artificial property parcels, and differences were summarized as graphs of percent difference between tonnage calculated from the grid and average tonnage from simulations. Coal in individual parcels was considered minable for valuation purposes if average thickness in each parcel exceeded 30 inches. Results of this study show that over 75% of the parcels are classified correctly as minable or unminable based on interpolation grids of coal bed thickness. Although between 80 and 90% of the tonnages differ by less than 20% between interpolated values and simulated values, a nonlinear conditional bias might exist in estimation of coal tonnage from interpolated thickness, such that tonnage is underestimated where coal is thin, and overestimated where coal is thick. The largest percent differences occur for parcels that are small in area, although because of the small quantities of coal in question, bias is small on an absolute scale for these parcels. For a given parcel size, maximum apparent overestimation of coal tonnage occurs in parcels with an average coal bed thickness near the minable cutoff of 30 in. Conditional bias in tonnage for parcels having a coal thickness exceeding the cutoff by 10 in. or more is constant for two of the three coals studied, and increases slightly with average thickness for the third coal.

Geostatistical Analysis of Oil Production and Potential Using Indicator Kriging

The State of West Virginia (eastern United States) taxes owners of coal that exceeds a specified threshold in thickness under their property. This criterion for minability does not account for uncertainty in the estimation of average coal thickness. A new criterion is proposed that uses conditional simulation to generate multiple realizations of coal thickness in a 7.5 minute quadrangle in West Virginia. From each simulated surface, the average thickness and total coal volume can be computed for each parcel. The total set of simulations is used to determine percentiles of average coal thickness by parcel. The proposed criterion requires that a given percentile of average values exceed the threshold for a parcel to be classified as minable, and therefore subject to taxation. This study shows the effect of criterion, parcel size, regional coal bed thickness, and sample size on the proportion of parcels determined to be minable.

Geology of the Devonian Marcellus Shale--Valley and Ridge province, Virginia and West Virginia--a field trip guidebook for the American Association of Petroleum Geologists Eastern Section Meeting, September 28-29, 2011

In their Perspective “New and ancient trace makers” (16 January, p. 346), S. Bengtson and B. Rasmussen implied that trace fossil workers (in general) assume that all trace fossils are the result of animal activities. According to the operational definition that I have used since student days,

Depositional History of a Middle Ordovician, Mixed-Carbonate-Clastic Unit - The Kanosh Formation, Eastern Great Basin, U.S.A.

The Preferred Upstream Management Practices (PUMP) project, a two-year study sponsored by the United States Department of Energy (USDOE), had three primary objectives: (1) the identification of problems, problematic issues, potential solutions and preferred practices related to oil production; (2) the creation of an Appalachian Regional Council to oversee and continue this investigation beyond the end of the project; and (3) the dissemination of investigative results to the widest possible audience, primarily by means of an interactive website. Investigation and identification of oil production problems and preferred management practices began with a Problem Identification Workshop in January of 2002. Three general issues were selected by participants for discussion: Data Management; Reservoir Engineering; and Drilling Practices. At the same meeting, the concept of the creation of an oversight organization to evaluate and disseminated preferred management practices (PMPs) after the end of the project was put forth and volunteers were solicited. In-depth interviews were arranged with oil producers to gain more insight into problems and potential solutions. Project members encountered considerable reticence on the part of interviewees when it came to revealing company-specific production problems or company-specific solutions. This was the case even though interviewees were assured that all responses would be held in confidence. Nevertheless, the following production issues were identified and ranked in order of decreasing importance: Water production including brine disposal; Management of production and business data; Oil field power costs; Paraffin accumulation; Production practices including cementing. An number of secondary issues were also noted: Problems associated with Enhanced Oil Recovery (EOR) and Waterflooding; Reservoir characterization; Employee availability, training, and safety; and Sale and Purchase problems. One item was mentioned both in interviews and in the Workshop, as, perhaps, the key issue related to oil production in the Appalachian region - the price of a barrel of oil. Project members sought solutions to production problems from a number of sources. In general, the Petroleum Technology Transfer Council (PTTC) website, both regional and national, proved to be a fertile source of information. Technical issues included water production, paraffin accumulation, production practices, EOR and waterflooding were addressed in a number of SPE papers. Articles on reservoir characterization were found in both the AAPG Bulletin and in SPE papers. Project members extracted topical and keyword information from pertinent articles and websites and combined them in a database that was placed on the PUMP website. Because of difficulties finding potential members with the qualifications, interests, and flexibility of schedule to allow a long-term commitment, it was decided to implement the PMP Regional Council as a subcommittee of the Producer Advisory Group (PAG) sponsored by Appalachian Region PTTC. The advantages of this decision are that the PAG is in already in existence as a volunteer group interested in problem identification and implementation of solutions and that PAG members are unpaid, so no outside funds will be required to sustain the group. The PUMP website became active in October of 2002. The site is designed to evolve; as new information becomes available, it can be readily added to the site or the site can be modified to accommodate it. The site is interactive allowing users to search within the PUMP site, within the Appalachian Region PTTC site, or within the whole internet through the input of user-supplied key words for information on oil production problems and solutions. Since its inception in the Fall of 2002, the PUMP site has experienced a growing number of users of increasingly diverse nature and from an increasing geographic area. This indicates that the site is reaching its target audience in the Appalachian region and beyond. Following up on a commitment to technology transfer, a total of eight focused-technology workshops were sponsored by the Appalachian Region PTTC center at the request of the PUMP project. Five Welltender Operations and Safety seminars were held in Kentucky, West Virginia, Ohio, and Pennsylvania. A two-day Applied Reservoir Characterization seminar and a one-day course on Paraffin, Asphaltene, and Scale problems were held in Pennsylvania. A one-day workshop on Produced Water was held in OH. In addition to workshops and the PUMP website, the project also generated several topical reports available to the public through the website and through USDOE.

Characterization of the Helderberg Group as a geologic seal for CO2 sequestration

Short-lived, basement-block movements initiated sedimentation in the early Middle Ordovician Kanosh basin. The basin was a north-south, elongate, intrashelf structure covering approximately 90,000 km/sup 2/ of Utah and Nevada, and was subdivided into the northern Utah and Ibex subbasins by the east-west-trending Tooele arch. The Kanosh Shale, an organic-rich (TOC less than or equal to 5.6%), graptolitic shale with numerous, thin, interbedded calcarenites, was deposited throughout the basin. Deposition began abruptly and was nearly synchronous, corresponding roughly to the base of macrofossil zone M, early Whiterock stage. The intertidal and shallow, subtidal carbonate sedimentation that preceded the Kanosh Shale continued in area surrounding the basin during Kanosh deposition; abrupt, local subsidence rather than regional sea level rise initiated Kanosh deposition. Basal sands of the lower Swan Peak quartzite and carbonates of the Lehman Formation encroaching on the basin terminated Kanosh deposition. Recurrent uplift of the Tooele arch during the deposition of these two units (middle and late macrofossil zone N, middle Whiterock) caused them to thin markedly over the axis of the arch; this effect is much less noticeable in the underlying Kanosh Shale.