Changes

{{publication  

{{publication  

  | image  = exploring-for-oil-and-gas-traps.png

  | image  = exploring-for-oil-and-gas-traps.png

  | series  = Treatise in Petroleum Geology

  | series  = Treatise in Petroleum Geology

  | title  = Exploring for Oil and Gas Traps

  | title  = Exploring for Oil and Gas Traps

  | part    = Traps, trap types, and the petroleum system

  | part    = Traps, trap types, and the petroleum system

  | chapter = Petroleum systems

  | chapter = Petroleum systems

  | frompg  = 3-1

  | frompg  = 3-25

  | topg    = 3-34

  | topg    = 3-26

  | author  = Leslie B. Magoon, Edward A. Beaumont

  | author  = Leslie B. Magoon, Edward A. Beaumont

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch03/ch03.htm

  | link    = http://archives.datapages.com/data/specpubs/beaumont/ch03/ch03.htm

==Petroleum province==

==Petroleum province==

'''Petroleum province''', a geographic term, is an area where petroleum occurs in commercial quantities. Basin is sometimes used geographically to mean petroleum province, such as the Williston Basin or Paris Basin. The Zagros fold belt could be a structural province or a petroleum province, not a basin.

'''Petroleum province''', a geographic term, is an area where petroleum occurs in commercial quantities. Basin is sometimes used geographically to mean petroleum province, such as the Williston Basin or Paris Basin. The Zagros [[fold]] belt could be a structural province or a petroleum province, not a basin.

A map showing differential thickness of sedimentary rocks is used to determine basins (thick), uplifts (thin), and fold belts (folded). These features are properly named provinces; if they contain petroleum, they are called petroleum provinces. The use of “basin” in this context is improper; it is also inconsistent with the petroleum system concept described below, which defines “basin” as the area into which sedimentary rocks are deposited.

A map showing differential thickness of sedimentary rocks is used to determine basins (thick), uplifts (thin), and fold belts (folded). These features are properly named provinces; if they contain petroleum, they are called petroleum provinces. The use of “basin” in this context is improper; it is also inconsistent with the [[petroleum system]] concept described below, which defines “basin” as the area into which sedimentary rocks are deposited.

==Sedimentary basin==

==Sedimentary basin==

A '''sedimentary basin''' is a depression filled with sedimentary rocks. The presence of sedimentary rocks is proof that a basin existed.

A '''sedimentary basin''' is a depression filled with sedimentary rocks. The presence of sedimentary rocks is proof that a basin existed.

The depression, formed by any tectonic process, is lined by '''basement rock''', which can be igneous, metamorphic, and/or sedimentary rock. The '''basin fill''' includes the rock matter, organic matter, and water deposited in this depression. In certain cases, such as with coal and some carbonate deposits, the sedimentary material is formed in situ. The essential elements of a petroleum system are deposited in sedimentary basins. Frequently, one or more overlapping sedimentary basins are responsible for the essential elements of a petroleum system. Traps are formed by tectonic processes that act on sedimentary rocks. However, the moment petroleum is generated, biologically or thermally, a petroleum system is formed.

The depression, formed by any tectonic process, is lined by '''[[basement]] rock''', which can be [[igneous]], metamorphic, and/or sedimentary rock. The '''basin fill''' includes the rock matter, organic matter, and water deposited in this depression. In certain cases, such as with [[coal]] and some carbonate deposits, the sedimentary material is formed in situ. The essential elements of a petroleum system are deposited in sedimentary basins. Frequently, one or more overlapping sedimentary basins are responsible for the essential elements of a petroleum system. Traps are formed by tectonic processes that act on sedimentary rocks. However, the moment petroleum is generated, biologically or thermally, a petroleum system is formed.

==Petroleum system==

==Petroleum system==

The play and prospect are used by the explorationist to present a geologic argument to justify drilling for undiscovered, commercial petroleum accumulations.

The play and prospect are used by the explorationist to present a geologic argument to justify drilling for undiscovered, commercial petroleum accumulations.

The '''play''' consists of one or more geologically related prospects, and a '''prospect''' is a potential trap that must be evaluated by drilling to determine whether it contains commercial quantities of petroleum. Once drilling is complete, the term “prospect” is dropped; the site becomes either a dry hole or a producing field.

The '''play''' consists of one or more geologically related prospects, and a '''prospect''' is a potential trap that must be evaluated by drilling to determine whether it contains commercial quantities of petroleum. Once drilling is complete, the term “prospect” is dropped; the site becomes either a [[dry hole]] or a producing field.

The presence of a petroleum charge, a suitable trap, and whether the trap formed before it was charged are usually involved in this evaluation.

The presence of a [[Calculating charge volume|petroleum charge]], a suitable trap, and whether the trap formed before it was charged are usually involved in this evaluation.

These terms are compared in the table below

These terms are compared in the table below

{| class = "wikitable"

{| class = "wikitable"

|-

|-

! Item to be Compared

! Item to be Compared || Sedimentary Basin || Petroleum System || Play || Prospect

! Sedimentary Basin

! Petroleum System

! Play

! Prospect

|-

|-

| Investigation

| Investigation || Sedimentary rocks || Petroleum || Traps || Trap

| Sedimentary rocks

| Petroleum

| Traps

| Trap

|-

|-

| Economics

| [[Economics]] || None || None || Essential || Essential

| None

| None

| Essential

| Essential

|-

|-

| Geologic time

| Geologic time || Time of deposition || Critical moment || Present day || Present day

| Time of deposition

| Critical moment

| Present day

| Present day

|-

|-

| Existence

| Existence || Absolute || Absolute || Conditional || Conditional

| Absolute

| Absolute

| Conditional

| Conditional

|-

|-

| Cost

| Cost || Very low || Low || High || Very high

| Very low

| Low

| High

| Very high

|-

|-

| Analysis

| Analysis

In a play, the petroleum accumulations are commercial and undiscovered. In a petroleum system, the petroleum occurrences are already discovered.<ref name=ch03r7>Magoon, L., B., 1995, The play that complements the petroleum system—a new exploration equation: Oil & Gas Journal, vol. 93, no. 40, p. 85–87.</ref> Other differences are listed in the table above. Usually, a play is predicated without any particular petroleum system in mind. However, when a play is based on a particular petroleum system, it is called a complementary play.

In a play, the petroleum accumulations are commercial and undiscovered. In a petroleum system, the petroleum occurrences are already discovered.<ref name=ch03r7>Magoon, L., B., 1995, The play that complements the petroleum system—a new exploration equation: Oil & Gas Journal, vol. 93, no. 40, p. 85–87.</ref> Other differences are listed in the table above. Usually, a play is predicated without any particular petroleum system in mind. However, when a play is based on a particular petroleum system, it is called a complementary play.

The petroleum system concept is used two ways in exploration. By mapping a petroleum system, an explorationist learns new play concepts to add new oil or gas fields to the petroleum system. This relation is shown in the following equation:

[[The petroleum system concept]] is used two ways in exploration. By [[Petroleum system: geographic, stratigraphic, and temporal extent|mapping a petroleum system]], an explorationist learns new play concepts to add new oil or gas fields to the petroleum system. This relation is shown in the following equation:

:<math>\mbox{PS}_{\rm total} = \mbox{PS}_{\rm partial} + \mbox{CP}_{1} + \mbox{CP}_{2} + \mbox{CP}_{3}</math>

:<math>\mbox{PS}_{\rm total} = \mbox{PS}_{\rm partial} + \mbox{CP}_{1} + \mbox{CP}_{2} + \mbox{CP}_{3}</math>

The petroleum system is also used as an analog to another less-explored petroleum system. For this approach to work, the explorationist must have a series of petroleum system case studies available for comparison.

The petroleum system is also used as an analog to another less-explored petroleum system. For this approach to work, the explorationist must have a series of petroleum system case studies available for comparison.

==References==

==References==

[[Category:Traps, trap types, and the petroleum system]]  

[[Category:Traps, trap types, and the petroleum system]]  

[[Category:Petroleum systems]]

[[Category:Petroleum systems]]