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Line 17: + + + − + − − [[file:evaluating-top-and-fault-seal_fig10-49.png|thumb|{{figure number|10-49}}Data from Vavra et al.<ref name=ch10r87 />).]]
Displacement pressure estimation from sedimentary facies and well logs (view source)
Revision as of 17:59, 5 February 2014
, 17:59, 5 February 2014→Example: Ardjuna basin, Indonesia
==Example: Ardjuna basin, Indonesia==
==Example: Ardjuna basin, Indonesia==
[[file:evaluating-top-and-fault-seal_fig10-49.png|thumb|{{figure number|1}}Data from Vavra et al.<ref name=ch10r87 />).]]
The top seal and capillary properties of rocks from the Ardjuna basin (offshore Java, Indonesia) are related to mappable facies.<ref name=ch10r87 /> The Talang Akar Formation consists of deltaic facies ranging from channel sandstones, delta plain shales, and channel abandonment siltstones to prodelta and delta-front shales as well as shelfal carbonates.
The top seal and capillary properties of rocks from the Ardjuna basin (offshore Java, Indonesia) are related to mappable facies.<ref name=ch10r87 /> The Talang Akar Formation consists of deltaic facies ranging from channel sandstones, delta plain shales, and channel abandonment siltstones to prodelta and delta-front shales as well as shelfal carbonates.
Each of these facies has a distinct range of displacement pressures. The following figure shows the range of seal capacities for the different facies. Shelfal carbonates and delta-front shales are excellent seals, with displacement pressures > 1000 psia (air-mercury) and capable of trapping approximately 1000–10,000 ft of oil. Delta-plain shales are relatively poor seals, with displacement pressures of 80–90 psia (air-mercury<sup>o</sup> and capable of trapping only 90–100 ft of oil.
Each of these facies has a distinct range of displacement pressures. [[:file:evaluating-top-and-fault-seal_fig10-49.png|Figure 1]] shows the range of seal capacities for the different facies. Shelfal carbonates and delta-front shales are excellent seals, with displacement pressures > 1000 psia (air-mercury) and capable of trapping approximately 1000–10,000 ft of oil. Delta-plain shales are relatively poor seals, with displacement pressures of 80–90 psia (air-mercury<sup>o</sup> and capable of trapping only 90–100 ft of oil.
These values place an upper limit on the amount of hydrocarbon that can be trapped. Other factors, however, limit the sealing potential of these seals. Seal risk was defined by combining P<sub>d</sub> with qualitative assessments of ductility, fracturing, thickness, and lateral continuity.<ref name=ch10r87 />
These values place an upper limit on the amount of hydrocarbon that can be trapped. Other factors, however, limit the sealing potential of these seals. Seal risk was defined by combining P<sub>d</sub> with qualitative assessments of ductility, fracturing, thickness, and lateral continuity.<ref name=ch10r87 />
==Example: onshore African basin==
==Example: onshore African basin==