Natural gas ultimate recovery growth modeling by plays in the Gulf Coast Basin

Estimates of ultimate recovery, the sum of the proved reserves and cumulative production up to a specific time, are initially conservative due to the lack of understanding of the geological, engineering, and production characteristics of the reservoir or field. Ultimate recovery tends on average to increase substantially over time and drilling due to better understanding of the reservoir or field and application of advanced technologies. In recent years, natural gas ultimate recovery growth has become a major component of total U.S. annual natural gas reserve additions.;Although there is a wide range in ultimate recovery growth potential by play and that potential is a function of the drilling and technology applied, current ultimate recovery growth studies are gross, averaging wide ranges, aggregated by broad provinces, and calculated solely as a function of time. An assessment on a play basis is the key to understanding the future role of natural gas ultimate recovery growth in the Gulf Coast Basin. Ultimate recovery growth varies according to plays because of different geological, engineering, and production characteristics and amenability to advanced recovery technology.;Natural gas ultimate recovery growth in Texas Railroad Commission (TX RRC) District 4 was initially analyzed on the basis of its role as a major natural gas producing district in the Gulf Coast Basin where significant technological advancements have been routinely applied. Significant ultimate recovery growth and future potential was observed for the total 520 major natural gas fields of TX RRC District 4. However, important ultimate recovery growth data were masked by such total, aggregated analysis.;Play analysis revealed important ultimate recovery growth trends and characteristics. Plays WX-2, WX-4, and VK-1 revealed significant future ultimate recovery growth potential. These plays are comprised of relatively recently discovered fields, especially play WX-2. Deeper reservoir depths of these plays have induced high structural complexities due to fault compartmentalization, reservoirs designated as tight gas/low-permeability, and high initial reservoir pressures.