Experimental Investigation on Sandstone Rock Permeability of Pakistan Gas Fields

Abstract

Abstract. Permeability is the ability of formation to produce hydrocarbon which is affected by compaction, pore size, sorting, cementation, layering and clay swelling. The effect of texture on permeability in term of grain size, sorting, sphericity, degree of cementing has been reported in literature. Also, the effect of permeability on capillary pressure, irreducible water saturation, displacement pressure and pore geometry constant has been studied separately. This preliminary study presents the experimental results of eight samples to understand the effect of similar factors of texture on permeability. With the knowledge of the results, it can be said that the effect of grain size, cementation, texture material, sphericity, and porosity can't be observed on permeability except sorting when less than ten samples are considered from different depositional environment. The results also show the impact of permeability on capillary pressure, irreducible water saturation, and displacement pressure and pore geometry index as similar as published in the literature.

A novel gas sands characterization and improved depositional modeling of the Cretaceous Sembar Formation, Lower Indus Basin, Pakistan

“…There is a slight decrease in permeability with depth, as shown by the trend line in Figure 15B. This low average of permeability is due to sandstone diagenesis, compaction, and overburden pressure at such a great depth, as compared to conventional sandstone permeabilities of other gas fields in Pakistan, as reported by Raza et al (2015). However, nevertheless, the permeability average is about 3.5 millidarcys, which is much higher than the tight-sandstone category having permeability less than 0.1 millidarcy (Zhang et al, 2012).…”

“…Permeability is also affected by and affects capillary pressure, displacement pressure, effective porosity, and irreducible water saturation. Lowest achievable water saturation by displacement through oil or gas up to a certain extent is known as irreducible water saturation (Raza et al, 2015). After the Tixier and Timur models proposed in 1949 and 1968, respectively, Coates and Dumanoir proposed their model of permeability estimation in 1974 (Balan et al, 1995).…”