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.

A Reservoir-scale Miocene Injectite near Santa Cruz, California

Abstract: The Yellow Bank creek complex (YBCC) is a large, upper Miocene injectite complex, one of numerous injectites northwest of Santa Cruz, California. The feeder for these injectites is the Santa Margarita Sandstone, a shelfal sandstone unit that is also the reservoir rock in several exhumed oil fields. The impermeable cap rock for these oil fields, the Santa Cruz Mudstone, was breached by sand injectites, some of which reached the sea floor. Located near the edge of one of these oil fields, the YBCC is a dike-sill complex that shows evidence for multiple phases of injection by fluidized sand that was initially gas or water saturated and later possibly oil bearing. Vertical injection of a large sand dike along a fracture was followed by lateral injection of a sill from the dike along bedding planes in the Santa Cruz Mudstone. Flow differentiation during injection of fluidized sand into the sill formed centimeter-scale layering in its lower part. Subsequent emplacement of oil into this sand may have occurred by injection and by seepage that displaced pore water, producing sand masses that became preferentially cemented by dolomite. Some evidence suggests that the injection and cementation occurred at relatively shallow burial depths beneath the sea floor, with the injection resulting from a combination of possible seismic shaking and migration of overpressured fluids from more deeply buried parts of the Santa Margarita Sandstone. A pervasive lamination marked by limonite staining developed following uplift and subaerial exposure of the complex, possibly in a groundwater environment.

Geology of the Point Arguello Discovery

Abstract: Chevron (as operator for its partners, Phillips, Champlin, and Impkemix) discovered the Point Arguello oil field in 1981. The discovery well, the Chevron et al P-0316-1, was drilled in federal waters 8.5 mi (13.7 km) south of Point Arguello, California. Delineation drilling has confirmed the discovery of a giant oil field with estimated recoverable reserves in excess of 300 million bbl of oil. The oil field is located within a small depocenter at the southern edge of the offshore Santa Maria basin. This local depocenter may contain over 15,000 ft (4,600 m) of Neogene rocks. The Point Arguello accumulation is trapped in a large north-northwest-trending anticlinal complex. The primary reservoir is the middle and upper Miocene Monterey Formation, composed of fractured cherts, porcellanites, siliceous mudstones, and dolostones. Calculated fracture permeabilities range up to 3 darcys. Crestal wells have indicated productivities, after acid, of approximately 6,000 BOPD.

Examination of the Importance of Self Diffusion in the Transportation of Gas in Shale Gas Reservoirs

Abstract: Since gas is very compressive, a gradient in gas pressure directly results in a gradient in gas concentration. In other words diffusive and advective transport processes are coupled. In the following, the coupled transport equations are written in terms of an effective transport coefficient that is the sum of a permeability term and a diffusion term. The relative values of these terms are evaluated for shale gas reservoir rocks both under temperature and pressure conditions typical of Bamett shale reservoirs. Measurements in the laboratory are also discussed. Evaluation of the diffusion term for Bamett type shale gas reservoirs shows that self diffusion in the gas phase is not an important transport process except for the lowest permeability rocks.