Undiscovered Oil and Gas Resources An Evaluation of the Department of the Interior's 1989 Assessment Procedures (1991) / Chapter Skim
Currently Skimming:
D Background: Components of the Petroleum Resource Base
D Background: Components of the Petroleum Resource Base
Pages 173-182
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 173... ...
In general, the historically evaluated recoverable portion of the in-place oil and gas resource base is composed of four main parts: cumulative production, proved reserves, indicated and inferred reserves, and undiscovered resources (see Figure 2.1) , which will be discussed below.
|
From page 174... ...
. Proved Reserves Proved reserves are those portions of in-place crude oil, condensate, natural gas, natural gas liquids, and associated substances that have been identified and are considered, on the basis of geologic and engineering data, to be recoverable under current economic and government regulatory conditions using existing technology.
|
From page 175... ...
Alternatively, when known, the results of the application of such techniques to similar reservoirs may be used to estimate additional indicated recovery. Inferred reserves are part of the identified economic resources that are expected to be added to proved reserves as new field wells are drilled to extend known fields, as earlier reserve estimates are revised, and as production is developed from new producing zones in known fields.
|
From page 176... ...
Many current resource estimates do not yet recognize extended reserve growth and some analysts suggest that these resources are part of inferred reserves. However, past methods of refining conventional reserve growth do not incorporate extended reserve growth, as past growth resulted from a different sort of field development.
|
From page 177... ...
Conventional Resources Resources in the conventional category include crude oil, natural gas, and natural gas liquids that exist as discrete accumulations in conventional reservoirs, in a fluid state amenable to extraction techniques employing the most current development practices. In the DOI assessment, conventionally recoverable resources are crude oil and natural gas accumulations that can be extracted from a well by the natural pressure within the reservoir, mechanical pumping to surface, or injection of water or gas to maintain reservoir pressure.
|
From page 178... ...
The speculative resource category of the PGC includes projected discoveries of new fields in non-producing strata located in either producing or · non-prot ucmg provinces. Unconventional Resources The term unconventional resources originally was applied to in-place resources of crude oil and natural gas not recoverable using existing or evolving technology, but which might be recoverable through the development of new technology.
|
From page 179... ...
The process by which vegetation is converted to coal over geologic time also generates large quantities of natural gas. Such natural gas is considered to be unconventional natural gas in the coal beds and conventional natural gas in adjacent permeable sedimentary strata.
|
From page 180... ...
3800 ~ + ) 3230 plants SOURCE: Derived from the Geological Society of America Time Scale, 1983.
|
From page 181... ...
Although individual oil fields vary in the rates at which they can be produced, on average only about one-tenth of the remaining recoverable crude oil can be efficiently removed from a reservoir each year. Withdrawal at faster average rates commonly will cause reservoir damage that will reduce ultimate production.
|
From page 182... ...
However, as fields grow, inferred reserves are converted to proved reserves and, as such, support production. Similarly, as undiscovered resources are converted to proved reserves, they also support production.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.