FIT-PGS Deep Hydrocarbon Prospectivity Evaluation, Offshore Texas/Gulf of Mexico
RESULTS
Present and Past Distribution of Petroleum
Petroleum Type and Quality
Proximal Undrilled Pay
Bypassed Pay
Seals and Pressure Compartments
Reservoir Compartments
Deep Prospectivity Under Shallow Borings
179 Wells; 24,000 Samples
Summary of Study and its Application:
PGS Reservoir (U.S.), Inc. (PGS) and Fluid Inclusion Technologies, Inc. (FIT) are pleased to announce a new non-exclusive study of the hydrocarbon prospectivity of offshore Texas. Focus of the study is twofold: First, potential gas sweetspots are defined in the main body of the deep overpressured shelf. Second, potential oil and condensate sweetspots are defined along Texas state waters and into the deeper water shelf and slope areas. As deepwater exploration interst moves further west in each succeeding lease sale, it is important to have a Texas strategy based on expected hydrocarbon type. This study provides information to help formulate such a strategy. Additionally, the study highlights liquid prospectivity in Texas state waters beyond limited areas of current production.Problem Statement:
Gas sweetspots in the deep overpressured shelf are difficult to locate and expensive to drill. They exist in wildcat areas and below established shallow production. Sweetspots commonly produce hundreds of BCF of gas, and some fields exceed a TCF. Within gas sweetspots, reservoirs often have large amounts of secondary porosity generated by dissolution of early carbonate cements and metastable silicate minerals. Reservoir enhancement occurs from late-moving fluids within the geopressure compartment. Later gas charging occurs along the same fluid conduit system. Outside sweetspot areas, reservoir quality and gas presence are major exploration risks. Clearly, a technique for discriminating deep gas sweetspots from surrounding non-prospective areas would help high grade acreage and reduce drilling risk. Although generally considered gas prone, portions of the offshore Texas shelf lie immediately adjacent to areas with prolific liquids production. Poorly defined boundaries separate Frio and Lower Miocene oil and gas production in coastal counties from predominantly gas production in Texas state waters. Mio-Plio- Pleistocene liquids production from the outer shelf and upper slope of eastern offshore Texas grades indistinctly westward into the Texas shelf. Between these two general boundaries lie the bulk of the Texas shelf -- an area of gas and highly variable condensate production.
Prior to the PGS-FIT study, no non-proprietary attempt had been made to systematically and rigorously analyze the distribution of hydrocarbon types of offshore Texas. Previous studies focused on detailed oil-typing analyses of liquids taken from relatively concentrated areas of known production. Little or no data were included between widely spaced fields. Generalized maps of historic production only hint at the hydrocarbon product type distributions that could be defined by more rigorous examination of wildcat wells. A storehouse of valuable wildcat information has been underutilized because appropriate technology has not been available, or has been too cumbersome to effectively apply on a regional basis. A study that defines the liquids potential of the Texas offshore areas based on both wildcat and producing wells could have great value in helping assess exploration potential and assign appropriate bid economics to prospective blocks.
Details of the Study: PGS Reservoir and FIT conducted a six-week program to analyze about 24,000 cuttings samples from 179 offshore wells. Fluid inclusions within the cuttings were mass spectrometrically analyzed for hydrocarbon and non-hydrocarbon volatile compositions. Wells were selected from field and wildcat locations to address the following questions:
- Is liquids potential fully defined for offshore Texas?
- Can deeper gas/condensate accumulations be geochemically detected from shallow drilling?
Additionally, data were analyzed to establish specific prospects for bypassed and near-miss pays. The report consists of:
- Maps illustrating the locations of 39 oil and gas leads based on the cumulative data generated during this study.
- Maps of historical production (for reference).
- Maps of gas, condensate and oil prospectivity in regional depth slices, based on FIS data.
- Maps illustrating other relevant FIS chemical data in regional depth slices.
- An interpretation of FIS data for each well as pertains to evidence for petroleum migration through the penetrated interval, evidence for proximal pay and evidence for fluid compartment boundaries (e.g., pressure seals).
- Photomicroscopic documentation of petroleum inclusions for type wells.
- Data report for each well, consisting of chemical depth logs and individual mass spectra for each sample analyzed.
- Complete FIS data (mass spectrometer responses for masses 2-180 for each sample) in ASCII and Excel format on compact disk.
Licensing Fee: $75,000 per company.
Phone: +918-461-8984
Fax: +918-461-2085
Fluid Inclusion Technologies, Inc.
"Innovations in Petroleum Risk Management"
2217 N. Yellowood Ave., Broken Arrow, OK 74012 USA
Email: fit@fittulsa.com
Web: www.fittulsa.com