Exploration and Production Technologies

Assessing and Forecasting, by Gas Play, Natural Gas Reserve Appreciation and Quantifying the Role of Technology Advancement in the Texas Gulf Basin and East Texas

DE-FG21-96MC33148

Goal: Conduct a detailed natural gas ultimate recovery growth (UGR) analysis of the Texas Gulf Coast Basin and East Texas.

Objective: In July 1996, the University of Texas at Austin expanded its Research and Development efforts to assess reserve growth on a play basis and to quantify the role of technology already applied as well as amenability of the specific play to future technology applications.

Detailed natural gas ultimate recovery growth (URG) analysis of the Texas Gulf Coast Basin and East Texas has been undertaken. The key to such analysis was determined to be the disaggregation of the resource base to the play level. The project has developed a realistic and play-specific measurement of remaining URG potential by natural gas resource volume. Through such assessment the longer term potential of natural gas URG as a contributor to future gas supply from the Texas Gulf Coast Basin and East Texas has been determined. Within Texas itself, the Gulf Coast Basin and East Texas comprise 67 percent and 58 percent of natural gas annual production and proved reserves, respectively. The Texas Gulf Coast Basin comprises Railroad Commission of Texas (RRC) Districts 1 through 4 and Offshore State waters. A total of 7,484 fields existed in the original 1996 Energy Information Administration’s (EIA) Oil and Gas Integrated Field File (OGIFF) data base. This data set was reduced to 1,372 fields that had 1996 natural gas ultimate recovery estimates greater than 10 Bcf and at least 2 years of data. This reduced data set represents 94 percent of the total 1996 natural gas ultimate recovery for the 7,484 fields. East Texas comprises RRC Districts 5 and 6 and a few fields extending into 3. A total of 1,447 fields existed in the original 1996 EIA OGIFF data base. This data set was reduced to 235 fields that had 1996 natural gas ultimate recovery estimates greater than 10 Bcf and at least 2 years of data. This reduced data set represents 96 percent of the total 1996 natural gas ultimate recovery for the 1,447 fields.

Major research objectives include: (1) developing a realistic and play-specific measure of remaining URG potential by natural gas resource volume for the Texas Gulf Coast Basin and East Texas, (2) an assessment of the technology necessary and most amenable to realizing the URG resource, and (3) assessing the economics of converting the resource to reserves. Through such assessment the longer term potential and cost of URG as a contributor to future natural gas supply from the Texas Gulf Coast Basin and East Texas can be determined. Further, the methodology for such an assessment can be verified and codified for wider extrapolation to other natural gas resource areas with significant URG potential.

Performer: University of Texas at Austin

Accomplishments:

  • Natural gas ultimate recovery estimates in the Texas Gulf Coast Basin increased approximately 30 percent (37 Tcf) within the 20-year data history frame from 1977 through 1996. Natural gas ultimate recovery estimates in East Texas increased approximately 74 percent (17 Tcf) within the same time frame.
  • Aggregated URG curves for the Texas Gulf Coast Basin and East Texas revealed significant URG. Texas Gulf Coast Basin and East Texas had an aggregated cumulative growth factor (CGF) of 8.28 and 33.5, respectively.
  • For the Texas Gulf Coast Basin, 1,369 fields were disaggregated into 30 geologically delineated plays. Only major plays with natural gas ultimate recovery greater than 1 Tcf were selected for detailed analysis. A total of 21 plays were selected for further detailed URG analysis. For East Texas, 246 fields were disaggregated into 14 individual plays. Ten major plays having significant natural gas ultimate recovery were selected for detailed analysis.
  • URG analysis by a factor of time using cumulative growth factors showed that plays WX-2, KG-2, KG-4, WX-1, WX-4, VK-1, and KG-1 in the Texas Gulf Coast Basin and the Lower Cretaceous-Jurassic Sandstone (KJ) plays in East Texas are experiencing the most growth. These plays all show URG trends above the total aggregated growth curves. These plays also show significant recent growth in terms of 1996 versus 1977 natural gas ultimate recovery ratios.
  • URG analysis by a factor of drilling activity revealed significant growth to be occurring in the Texas Gulf Coast Basin and East Texas. When yields per effort were compared, plays WX-4, WX-2, WX-1, VK-1, MC-4, KG-1, and FR-2 in the Texas Gulf Coast Basin and the Jurassic Carbonate (JC) and the Lower Cretaceous-Jurassic Sandstone (KJ) plays in East Texas were above the total aggregated yield per effort.
  • On the basis of both time and drilling activity, the top plays found to have the greatest current and future potential for natural gas URG were WX-2, WX-4, WX-1, and VK-1 in the Texas Gulf Coast Basin and the Lower Cretaceous-Jurassic Sandstone (KJ) plays in East Texas.
  • Plays experiencing the greatest URG were characterized by relatively recently discovered fields, greater reservoir depths and pressures, high structural complexities due to fault compartmentalization, and reservoirs designated as tight gas/low permeability.
  • Technologies most amenable and currently applied to plays experiencing the most URG were determined to be 3-D seismic, horizontal/directional drilling, and hydraulic fracturing techniques.
  • The Texas Gulf Coast Basin was forecast to have 43,734 future incremental well completions to contribute approximately 13 Tcf to URG by Year 2015. East Texas was forecast to have 14,655 future incremental well completions to contribute approximately 5 Tcf to URG by Year 2015. URG forecast by the Year 2030 in the Texas Gulf Coast Basin and East Texas was approximately 22 and 8 Tcf, respectively.
  • For the Texas Gulf Coast Basin, plays WX-4, VK-1, and WX-2 hold the greatest URG potential by Year 2030. These three plays comprise approximately 50 percent of the total natural gas URG potential in the Texas Gulf Coast Basin. For East Texas, the Lower Cretaceous-Jurassic Sandstone (KJ) plays account for approximately 59 percent of the total natural gas URG potential by Year 2030.

Current Status and Remaining Tasks: This project has been completed and a final report is provided below.

Project Start Date: July 30, 1996
Project End Date: December 31, 2000

Anticipated DOE Contribution: $ 425,000
Performer Contribution: $ 50,000

Contact Information:
NETL - Gary L. Covatch (304-285-4589 or gary.covatch@netl.doe.gov)

Additional Information:
Final Report [PDF-6657KB]

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