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.

Exploration trends of the Halten Terrace

Abstract: The Halten Terrace is a broad fault terrace located between the Trondelag Platform and the More Basin on the mid-Norwegian continental shelf (64°–65°3′N). The terrace contains a normal faulted pre-rift sequence draped by a syn-rift sequence of variable thickness and a thick post-rift sequence. The hydrocarbon plays are due to the occurrence of mature Early Jurassic coal-bearing gas-condensate source rock and the Late Jurassic Spekk Formation oil source rock. Three plays can be recognized. The pre-rift play covers a northeastern fairway which contains a number of commercial fields, and is characterized by a hydrostatic reservoir pressure or low-grade overpressure. To the west the reservoir sequence is deeper buried, greatly overpressured and exploration has so far been unsuccessful. The play is widely explored but there still remain large, high-risk gas prospects in the overpressured Halten West area. The syn-rift play reservoirs are thought to be present in submarine fan systems on the hanging-wall blocks of the Vingleia Fault Zone, which received erosion products from the uplifted Froya High to the south. Shallow marine shoreline and offshore bar sands are present on the major tilted footwall blocks along the edge of the Froya High (Draugen-Rogn Formation) and along the edge of the Sklinna High. The play is in its early exploration phase and the oil potential is considerable. The post-rift play relies on stratigraphic trapping in post-rift, Lange, Lysing and Nise sands on the Sklinna Saddle and in the Grinna Graben, where the sands may have been distributed further southwest from the uplifted and truncated Nordland Ridge. A thin Lysing Formation is oil-bearing in the Smorbukk Sor area. The stratigraphic trap potential of the post-rift play has not yet been tested and the play is thought to have a considerable oil potential. Exploration in the early and mid 1980's was focused on structural traps of the pre-rift play, which has yielded all the commercial fields except Draugen. Recent exploration is directed towards the oil potential of stratigraphic traps of the syn-rift and the post-rift plays and small pre-rift prospects in the vicinity of future production facilities.

Geologic Aspects of Tight Gas Reservoirs in the Rocky Mountain Region

Abstract: The Rocky Mountain region contains major gas resources in tight (low-permeability) reservoirs of Cretaceous and Tertiary age. These reservoirs usually have an in-situ permeability to gas of 0.1 md or less and can be classified into four general geologic and engineering categories: marginal marine blanket, lenticular, chalk, and marine blanket shallow. Microscopic study of pore/permeability relationships indicates the existence of two varieties of tight reservoirs. One variety is tight because of the fine grain size of the rock. The second variety is tight because the rock is relatively tightly cemented and the pores are poorly connected by small pore throats and capillaries. Other characteristics of tight gas reservoirs are: discrete gas/water contacts are absent in lenticular and marginal marine blanket reservoirs; most of the gas occurs in stratigraphic traps; well log analysis is difficult in tight reservoirs; many Rocky Mountain tight gas basins are either overpressured or underpressured; and formation damage may occur when wells are drilled and completed.