Petroleum reservoir

About: Petroleum reservoir is a research topic. Over the lifetime, 5403 publications have been published within this topic receiving 83535 citations. The topic is also known as: petroleum deposit.

Petroleum system in deepwater basins of the northern South China Sea

Abstract: The northern South China Sea margin has experienced a rifting stage and a post-rifting stage during the Cenozoic. In the rifting stage, the margin received lacustrine and shallow marine facies sediments. In the post-rifting thermal subsidence, the margin accumulated shallow marine facies and hemipelagic deposits, and the deepwater basins formed. Petroleum systems of deepwater setting have been imaged from seismic data and drill wells. Two kinds of source rocks including Paleogene lacustrine black shale and Oligocene-Early Miocene mudstone were developed in the deepwater basin of the South China Sea. The deepwater reservoirs are characterized by the deep sea channel fill, mass flow complexes and drowned reef carbonate platform. Profitable capping rocks on the top are mudstones with huge thickness in the post-rifting stage. Meanwhile, the faults developed during the rifting stage provide a migration path favourable for the formation of reservoirs. The analysis of seismic and drilling data suggests that the joint structural and stratigraphic traps could form giant hydrocarbon fields and hydrocarbon reservoirs including syn-rifting graben subaqueous delta, deepwater submarine fan sandstone and reef carbonate reservoirs.

Fluvial Architecture and Reservoir Compartmentalization in the Oligocene Middle Frio Formation, South Texas

Abstract: Seeligson, Stratton, and Agua Dulce fields (South Texas) are being studied as part of a Gas Research Institute/Department of Energy/State of Texas cosponsored program designed to develop and test methodologies and technologies for gas reserve growth in conventional reservoirs in mature gas fields. Over the last five decades, each field has produced approximately 2 Tcf of gas from middle Frio reservoirs alone. Recent drilling, old-well workover results, and reservoir pressure data, however, point to the possibility of additional reserves within these fields. The middle Frio (Oligocene) is composed of sand-rich channel-fill and splay deposits interstratified with floodplain mudstones, all forming part of the Gueydan fluvial system. Channel-fill deposits are 30 ft (9 m) thick and 2,500 ft (76 m) wide. Splay deposits are as much as 20 ft (6 m) thick proximal to channels and extend as much as 2 mi (3 km) from channels. Channel-fill and associated splay sandstones are reservoir facies (porosity = 20 percent; permeability = 10's to 100's md); floodplain mudstones and levee sandy mudstones impede or obstruct flow and separate individual reservoirs and compartments both vertically and laterally. Deposition on an aggrading coastal plain resulted in a continuum of fluvial architectural styles that has important implications for reservoir compartmentalization. Relatively slow aggradation resulted in laterally stacked channel systems, whereas more rapid aggradation resulted in vertically stacked channel systems. In Seeligson field, laterally stacked architecture alternates with vertically stacked architecture through the 2,000-ft- (610-m-) thick middle Frio section. In Stratton and Agua Dulce fields, the same general alternation in architectural modes exists through the 2,500-ft- (763-m-) thick middle Frio section. In Stratton and Agua Dulce, however, the reservoir zones composed of laterally stacked architecture are not laterally continuous; instead, the laterally stacked architecture locally changes into a vertically stacked architecture. Because laterally stacked sandstone bodies lead to separate but potentially "leaky" reservoir compartments and vertically stacked sandstone bodies favor more "isolated" reservoir compartments, a high potential for reserve growth through the identification of untapped, poorly drained, and bypassed gas reservoir compartments exists in each of these fields. Differences in reservoir architecture also must be taken into account as part of exploitation strategies.

The Optimization Of Well Spacing And Fracture Length In Low Permeability Gas Reservoirs

Abstract: This study describes a process for optimizing well spacing and fracture length in a low permeability gas reservoir. Three examples are discussed which represent a high permeability, a low permeability, and a medium permeability gas reservoir. The results from these investigations suggest that the solution is not always intuitively obvious. The complex interaction of the variables involved in each problem almost necessitates the use of a computer model to optimize the exploitation of a tight gas reservoir. Numerous computer runs have been made to illustrate the economic optimum fracture lengths for a variety of reservoir cases.