Changes

* Although several approaches could be used to quantify uncertainty in models, the approach presented uses Monte Carlo simulation. Monte Carlo simulation has the advantage of being (1) able to handle any probability distribution function, (2) able to account for dependencies between variables, and (3) straightforward to implement. It is also typically straightforward to analyze the results of the Monte Carlo simulation. The disadvantages include that it may require a large number of realizations to adequately sample the possible solution space, and it may be difficult to adequately develop probability distribution functions or the required realizations, particularly for maps and volumes.

* Although several approaches could be used to quantify uncertainty in models, the approach presented uses Monte Carlo simulation. Monte Carlo simulation has the advantage of being (1) able to handle any probability distribution function, (2) able to account for dependencies between variables, and (3) straightforward to implement. It is also typically straightforward to analyze the results of the Monte Carlo simulation. The disadvantages include that it may require a large number of realizations to adequately sample the possible solution space, and it may be difficult to adequately develop probability distribution functions or the required realizations, particularly for maps and volumes.

[[File:H4CH12FG2.JPG|thumb|300px|{{figure number|2}}Present-day depth structure map (meters) of the key migration surface. The outlines of the drainage polygons are shown in black, the closures are outlined in red, and the escape paths are shown in green. The scale bar in the legend represents 12,500 m (41,010 ft).]]

H4CH12FG2.JPG|{{figure number|2}}Present-day depth structure map (meters) of the key migration surface. The outlines of the drainage polygons are shown in black, the closures are outlined in red, and the escape paths are shown in green. The scale bar in the legend represents 12,500 m (41,010 ft).

H4CH12FG3.JPG|{{figure number|3}}Cross section through the model along the line AA' shown in [[:file:H4CH12FG2.JPG|Figure 2]].

A hypothetical example is presented to illustrate the approach described. Although the geology is synthetic, it was constructed with realistic basin modeling issues in mind. In this example, the traps of interest formed about 15 Ma. The primary question addressed by the model is, “What is the volume of oil charge to each of the traps during the last 15 m.y.?”

A hypothetical example is presented to illustrate the approach described. Although the geology is synthetic, it was constructed with realistic basin modeling issues in mind. In this example, the traps of interest formed about 15 Ma. The primary question addressed by the model is, “What is the volume of oil charge to each of the traps during the last 15 m.y.?”

For the purposes of this illustration, the migration analysis has been simplified, and it has been assumed that a present-day map-based drainage analysis is sufficient. A map view of the key surface for the map-based drainage analysis is shown in [[:file:H4CH12FG2.JPG|Figure 2]], and a cross section through the model is shown in [[:file:H4CH12FG3.JPG|Figure 3]]. A burial history curve at location X in [[:file:H4CH12FG2.JPG|Figure 2]] is shown in [[:file:H4CH12FG4.JPG|Figure 4]]. Also shown in [[:file:H4CH12FG4.JPG|Figure 4]] are three potential hydrocarbon source rocks, Upper [[Jurassic]], Lower [[Cretaceous]], and lower [[Miocene]]. The sources are modeled as uniformly distributed [[marine]] [[source rock]]s with some terrigenous input.

For the purposes of this illustration, the migration analysis has been simplified, and it has been assumed that a present-day map-based drainage analysis is sufficient. A map view of the key surface for the map-based drainage analysis is shown in [[:file:H4CH12FG2.JPG|Figure 2]], and a cross section through the model is shown in [[:file:H4CH12FG3.JPG|Figure 3]]. A burial history curve at location X in [[:file:H4CH12FG2.JPG|Figure 2]] is shown in [[:file:H4CH12FG4.JPG|Figure 4]]. Also shown in [[:file:H4CH12FG4.JPG|Figure 4]] are three potential hydrocarbon source rocks, Upper [[Jurassic]], Lower [[Cretaceous]], and lower [[Miocene]]. The sources are modeled as uniformly distributed [[marine]] [[source rock]]s with some terrigenous input.

===Step 1: identify the purpose of the model===

===Step 1: identify the purpose of the model===