Effective porosity

About: Effective porosity is a research topic. Over the lifetime, 1199 publications have been published within this topic receiving 26511 citations.

Diagenetic Processes Overprint and Pore Types of Mauddud Formation, Badra Oil Field, Central Iraq

Abstract: Diagenetic processes and types of pores that control the reservoir properties are studied for Mauddud Formation in selected wells of Badra oil field, central Iraq The microscopic study of the thin sections shows the effects of micritization, cementation, neomorphism, dissolution, dolomitization, compaction, and fracturing on Mauddud Formation carbonate microfacies The decrease of porosity is resulted from cementation, compaction, and neomorphism Different types of calcite cement occlude pore spaces such as drusy cement, syntaxial rim cement, and granular (blocky) cement The neomorphism of micritic matrix and skeletal grains reduces porosity as indicated by development of microspar or pseudospar Evidence of decreasing porosity by compaction includes closer packing of grains, which reduces interparticle porosity Dissolution process has prominent effect in creating and increasing the effective porosity in different depositional textures of Mauddud Formation Reservoir properties are increased in grain-supported microfacies, which have vuggy porosity or primary porosity, whose pore size differs depending on the size of the grains The reservoir properties in the mud-supported microfacies are reduced due to the low occurrence of pores and their lack of connectivity if they exist

Research on the Law of Porosity of Rock with Depth

Abstract: Porosity is an important parameter characteristized physical, mechanical and seepage properties of rock. In general, when seepage problem of rock is studied in shallow underground rock in natural condition, porosity of rock is taken as a constant. However, porosity of rock changes with depth, geostress and engineering forces. Through analysis of triaxial test of rock samples, it is discovered that there is a quartic polynomial relation between porosity of rock and depth and porosity of rock decreases with depth increase. Porosity of rock approximates to a constant under 6000 m～7000 m depths.

Reservoir Characterisation Of Johansen Formation As Potential CO2 Storage Reservoir In The Northern North Sea

Abstract: To evaluate subsurface reservoirs for CO2 sequestration, the grain scale properties and role of diagenesis is important for the injectivity and the subsequent mobilization. This study focuses on Johansen Formation of Jurassic age in the vicinity of Troll field within the northern North Sea. Johansen Formation is a saline aquifer and no hydrocarbon discovery has been reported in this reservoir so far. We analysed 24 wells using petrophysics and rock physics techniques to obtain net reservoir, net to gross ratio, effective porosity, volume of shale and level of cementation, and attempted to relate these parameters with the factors influencing them. The reservoir properties were found to be optimal approximately around depths shallower than 2000m (below sea floor, BSF). Even the shallowest sandstones exhibited cementation indicating calcite precipitation while the sediments deposited. Presence of shale however found to inhibit the quartz cementation possibly preserving the porosity. These findings will help understanding the complexity of the Johansen Sandstone as storage reservoir and the influence of heterogeneity on CO2 migration.