Abstract

Core storage and curation has been an issue since the day after the first core was taken in the Permian Basin. With the changing dynamics of the domestic oil industry, however, cores are often the first to go in donations, sales and efforts to cut costs. Efforts to preserve the access to core are being undertaken by the Bureau of Economic Geology, New Mexico Bureau of Geology and Mineral Resources, and a number of universities. There is an industry driven USGS initiative to develop a national core and sample repository: however, this facility is a long-term goal.

The short-term goal is to establish a Regional Core Storage Facility in the Permian Basin. The University of Texas of the Permian Basin, thru the Center for Energy and Economic Diversification and the Petroleum Industry Alliance, in conjunction with the Bureau of Economic Geology, is attempting to bring such a facility into being There is already a core layout facility at CEED. A 100,000 sq ft regional core storage facility, run by the BEG and sited at CEED, is in the planning stage. The cost of the project is estimated to be $2,000,000 for which state funds do not exist.

Core Storage and Curation

Operators in the Permian Basin have had a 75-year history of successful reservoir development, maintenance, and characterization, in large part due to the utilization of core in reservoir understanding and description. In the 1970’s every major oil company had at least one core storage facility in the Permian Basin. Over the past 20 years however, long-term core storage and curation has become increasingly endangered. Prior to the boom in the late 1970’s and early 1980’s, major oil companies were already experiencing difficulty in curating cores as warehouses, many built in the 1930’s, 1940’s and 1950’s, became filled and/or fell into disrepair.

With the downturn in the mid 1980’s, and the splintering of large fields, the cost of core storage and maintaining core storage facilities became an issue with many companies. With the migration offshore and the merger trend of the past 15 years, many of the companies donated their core to universities outside of the Permian Basin, included the core as part of property sales, or disposed of core outright. It is sometimes difficult to determine the ultimate fate of a particular core. Often it is only by the luck of the draw that important cores are available for reservoir studies. Smaller companies often do not have the space or inclination to take cores when purchasing properties. In many cases, cores had already “gone missing” when an operator begins a reservoir study and all that remains are core analyses. As a result of a number of successful, DOE sponsored studies, independent operators understand the necessity of core study in reservoir characterizations, but are cost limited in taking new cores for waterflood studies.

In the long term, the cost of core curation is not great when compared to the cost of replacing old “lost” core with core in a new well. Although it is difficult if not impossible to place a value on stored core, the hidden costs of not having the core available are tremendous. Without knowledge of future possible reservoir characterization studies, geologists cannot predict when a core will be studied. In addition, there is the “been there – done that” attitude of once a core has been described, it need not be looked at again.

The value of the core cannot be overstated. Most of the major oil company domestic research facilities have been closed and their “in house” expertise lost. These resources vanish as the experienced “rock docs” retire, leave the domestic arena or enter academia.

Core Studies

In the future, advances in the science must come from universities and state surveys, including the BEG. Most universities, however, have a premium on storage space and unless the donations are attached to research dollar donations, the number of cores that can be housed in long-term storage is limited. The value of a regional core facility coupled with industry-trained experts available to assist companies with reservoir characterization projects is incalculable. CEED and UPTB are attempting to develop such a program, wherein expertise would be available to assist independents in conducting successful reservoir characterization projects.

A core layout room has already been built in the CEED facility and some core storage developed. Included in the core layout room are enough tables to lay out 300’ of core, microscopes, cameras and stands, uv lights, thin sectioning equipment, a large fume hood, and black and magnetic white boards. The core layout room is available to the industry for viewing the donated core or for studying their own core for a nominal fee. Arrangements can be made for the staff and/or faculty and students at UTPB to be available to work with companies on core description and reservoir characterization projects.

A significant number of cores (>80) have been donated to UTPB and are being made available to students for study. These wells, totaling more than 6000’ would otherwise have been “lost”. Some of the core had “passed thru” 2 or more companies before being donated, with significant thicknesses of wind blown silts having been deposited on the box lids in the interim. These cores will be used as the basis for reservoir characterization-type masters theses. This type of project prepares the students to enter the workforce with a higher level of understanding of the reservoirs in the Permian Basin. The skills learned will be transferable to other reservoirs around the world.

Among the donated core are approximately 20 suites of from 2 to 6 cores from a particular field or area. The reservoirs include: eroded Fusselman and Montoya, Strawn buildups, karsted Lower Cisco carbonates, Wolfcamp buildups and debris flows, Cherry Canyon and Ramsey sands, karsted San Andres carbonates, Grayburg shelf carbonates and Queen shelf elastics. There are additional individual wells scattered across the basin. These cores will be used as the basis for regional studies, depositional environment studies, and diagenesis and reservoir characterization-type masters theses. These projects will prepare students to enter the workforce with a higher level of understanding of the reservoirs in the Permian Basin. The skills learned will be transferable elsewhere in the petroleum industry.

Through the Petroleum Industry Alliance (PIA), UTPB is attempting to provide technology transfer activities and events, conceive and conduct research, including reservoir characterization projects related to Permian Basin oil and gas development and act as an effective catalyst for bringing oil, gas and alternative energy projects to the Permian Basin.

There are more than 20 potential Masters Theses lurking (or promised) in the Core Storage at CEED.