3.6. Secondary Gas Recovery (1987-1995)
In 1992 the National Petroleum Council estimated that a resource base of 1,295 trillion
cubic feet (Tcf) of technically recoverable natural gas resources (including proved
reserves, conventional resources, and non-conventional resources) existed in the United
States.
Of that resource base, 216 Tcf was determined to be recoverable through reserve
appreciation in existing fields in the lower 48 states.
Reserve appreciation is the increase
in estimated reserves over original field estimates as enhanced geological understanding
and improved production technologies are developed and applied.
The integrated
application of concepts and cost-effective technologies from the disciplines of geology,
engineering, geophysics, and petrophysics are required for converting these resources
into producible reserves.
Natural gas reserve appreciation in conventional reservoirs has multiple components.
Historically, field extensions through offset development well drilling and deeper pool
drilling have been the way to add reserves.
Recompletions of existing wells were often
made without the benefit of a complete understanding of the reservoir’s heterogeneity or
compartmentalization. Where significant geologic variation occurs, incompletely drained
or bypassed reservoir compartments remain to be drained by new infield drilling or
strategically placed recompletions (Figure 3.6.1).
Figure 3.6.1: Schematic of Reservoir Compartmentalization. (Click image to enlarge)
In the last two decades,
characterization of the internal geometry of reservoirs has revealed a much higher degree
of compartmentalization than previously recognized.
This compartmentalization (other
than structural compartmentalization) is primarily a function of the depositional system
and, secondarily, of the diagenetic history of the reservoir after deposition.
The Secondary Natural Gas Recover (SGR): Targeted Technology Applications for
Infield Reserve Growth was a joint venture research project sponsored by the U.S.
Department of Energy (DOE), the Gas Research Institute (GRI), the State of Texas
through the Bureau of Economic Geology at The University of Texas at Austin, and the
natural gas industry.
DOE leveraged $8.5 million in federal funding with $6.5 million
from GRI, $1 million from Texas and $6.3 million from industry to support a 5-year
proof-of-concept project. The SGR project was a field-based program employing a
multidisciplinary approach that integrated geology, geophysics, engineering, and
petrophysics.
A major objective of this research project was to develop, test, and verify
those technologies and methodologies that would have near- to mid-term potential for
maximizing recovery of gas from conventional reservoirs in known fields. The new
technologies to be developed and applied included 3-D seismic and vertical seismic
profiling.
The Bureau of Economic Geology at the University of Texas led the SGR team
and coordinated the research, first in the onshore Texas Gulf Coast Basin and then in the
Ft. Worth Basin.
- Please bookmark this page (add it to your favorites).
Copyright © 1995-2010 ITA all rights reserved.
|
