Changes

Paleogeographic maps of the most important [[reservoir]]s and [[source rock]]s are shown in [[:file:M114CH03FG05.jpg|Figure 5]]). The most prolific reservoir is the late [[Cretaceous]] to early [[Paleocene]] [[synrift]] [[Fatehgarh Formation]]. The Fatehgarh Formation forms thick, sheet-like [[fluvial]] [[reservoir]]s that are best developed in the northern part of the basin (see [[:file:M114CH03FG05.jpg|Figure 5A]]). Fatehgarh Formation fluvial facies inter-digitate with basin margin [[alluvial]] [[fan]]s of the [[Jogmaya Mandir Formation]] in the north and the [[Dhandlawas Formation]] in the center and south of the basin, where they are composed of lower-quality [[volcaniclastic]] sands particularly well developed around the Central Basin High. These Fatehgarh Formation reservoirs are directly overlain by the main source rock in the basin, the [[lacustrine]] [[shales]] of the [[Sarovar Member]] of the [[Barmer Hill Formation]] ([[:file:M114CH03FG05.jpg|Figure 5B]]). [[Migration]] from these source rocks into the Fatehgarh Formation reservoirs is therefore either downward or across [[fault]] juxtapositions and highly efficient. The fan [[delta]] and lacustrine [[turbidite]] sands of the Barmer Hill Formation are easily charged with [[hydrocarbon]]s as they interdigitate with and are enclosed within the source rock. The Barmer Hill Formation also contains widespread [[diatomite]] deposits of the [[Bariyada Member]] (see [[:file:M114CH03FG05.jpg|Figure 4]]) that are intimately interbedded with the source rocks, forming a significant, laterally extensive but low permeability reservoir (Chowdhury et al., 2011<ref name=Chowdhuryetal2011>Chowdhury, M., M. Singhal, V. Sunder, T. O’Sullivan, P. A. Hansen, and S. D. Burley, 2011, Reservoir characterization of the low permeability siliceous Barmer Hill Formation, Barmer Basin, India: Society of Petroleum Engineers, v. SPE-146474-PP, p. 11–18.</ref>).

Paleogeographic maps of the most important [[reservoir]]s and [[source rock]]s are shown in [[:file:M114CH03FG05.jpg|Figure 5]]). The most prolific reservoir is the late [[Cretaceous]] to early [[Paleocene]] [[synrift]] [[Fatehgarh Formation]]. The Fatehgarh Formation forms thick, sheet-like [[fluvial]] [[reservoir]]s that are best developed in the northern part of the basin (see [[:file:M114CH03FG05.jpg|Figure 5A]]). Fatehgarh Formation fluvial facies inter-digitate with basin margin [[alluvial]] [[fan]]s of the [[Jogmaya Mandir Formation]] in the north and the [[Dhandlawas Formation]] in the center and south of the basin, where they are composed of lower-quality [[volcaniclastic]] sands particularly well developed around the Central Basin High. These Fatehgarh Formation reservoirs are directly overlain by the main source rock in the basin, the [[lacustrine]] [[shales]] of the [[Sarovar Member]] of the [[Barmer Hill Formation]] ([[:file:M114CH03FG05.jpg|Figure 5B]]). [[Migration]] from these source rocks into the Fatehgarh Formation reservoirs is therefore either downward or across [[fault]] juxtapositions and highly efficient. The fan [[delta]] and lacustrine [[turbidite]] sands of the Barmer Hill Formation are easily charged with [[hydrocarbon]]s as they interdigitate with and are enclosed within the source rock. The Barmer Hill Formation also contains widespread [[diatomite]] deposits of the [[Bariyada Member]] (see [[:file:M114CH03FG05.jpg|Figure 4]]) that are intimately interbedded with the source rocks, forming a significant, laterally extensive but low permeability reservoir (Chowdhury et al., 2011<ref name=Chowdhuryetal2011>Chowdhury, M., M. Singhal, V. Sunder, T. O’Sullivan, P. A. Hansen, and S. D. Burley, 2011, Reservoir characterization of the low permeability siliceous Barmer Hill Formation, Barmer Basin, India: Society of Petroleum Engineers, v. SPE-146474-PP, p. 11–18.</ref>).

The overlying [[Dharvi Dungar Formation]] is a [[lacustrine]], mud-dominated sequence that is also a significant [[source rock]] (Farrimond et al., 2015<ref name=Farrimondetal2015 />) and a major, thick regional [[sea]]l across the basin, providing a widespread barrier to vertical [[hydrocarbon migration]], only breached by young [[fault]]s related to basin inversion and fault reactivation ([[:file:M114CH03FG04.jpg|Figure 4]]). [[Fluvial]] reservoirs formed during lake level low-stands occur in the Dharvi Dungar Formation at a variety of levels, most notably the [[Giral Member]], but are productive only in the south of the basin ([[:file:M114CH03FG05.jpg|Figure 5C]]). These reservoirs are fine-grained, thin, and highly compartmentalized, and therefore difficult to charge with [[hydrocarbon]]s except where local sourcing from their enclosing or underlying [[shale]]s is possible. Productive deep-water lacustrine [[turbidite]]s are also present in the [[Mandai Member|Mandai]] and [[Kapurdi member]]s of the Dharvi Dungar Formation. Fluvial reservoirs are locally charged on the Central Basin High in the shallower [[Thumbli Formation]] where [[basement]]-related faults propagate into the [[Eocene]] section.

The overlying [[Dharvi Dungar Formation]] is a [[lacustrine]], mud-dominated sequence that is also a significant [[source rock]] (Farrimond et al., 2015<ref name=Farrimondetal2015 />) and a major, thick regional [[sea]]l across the basin, providing a widespread barrier to vertical [[hydrocarbon migration]], only breached by young [[fault]]s related to basin inversion and fault reactivation ([[:file:M114CH03FG04.jpg|Figure 4]]). [[Fluvial]] reservoirs formed during lake level low-stands occur in the Dharvi Dungar Formation at a variety of levels, most notably the [[Giral Member]], but are productive only in the south of the basin ([[:file:M114CH03FG05.jpg|Figure 5C]]). These reservoirs are fine-grained, thin, and highly compartmentalized, and therefore difficult to charge with [[hydrocarbon]]s except where local sourcing from their enclosing or underlying [[shale]]s is possible. Productive deep-water [[lacustrine]] [[turbidite]]s are also present in the [[Mandai Member|Mandai]] and [[Kapurdi member]]s of the Dharvi Dungar Formation. Fluvial reservoirs are locally charged on the Central Basin High in the shallower [[Thumbli Formation]] where [[basement]]-related faults propagate into the [[Eocene]] section.

==See also==

==See also==

* [[Silurian Qusaiba shales]]

* [[Silurian Qusaiba shales]]

==References==

==References==