Impact of fluid characterization on compositional gradient in a volatile oil reservoir

Abstract

Compositional gradient known as a potential of vertically variations in composition (and sometimes areal changes) has a remarkable effect on reservoir management steps such as estimation of initial hydrocarbon in place, design of downstream equipments and prediction of gas-oil contact. One of the main steps in development of compositional grading is to characterize fluid sample. In this study, compositional grading is studied in a volatile oil sample from an oil field in south of Iran. Implemented models are based on isothermal and non-isothermal, i.e., zero diffusion, Hasse and Kempers models. Results illustrated that isothermal and zero diffusion models are in appropriate consistency with field data. Then, effect of C 10? splitting on compositional grading was studied. It was shown that splitting of C 10? to more pseudo-components does not have significant effect on variation in composition of hydrocarbon and non-hydrocarbon components.

A semi-empirical method for predicting GOC in oil reservoirs with limited PVT dataset

“…Contrary to the general view that compositional grading depends on fluid samples and their characterization, Kiani et al [9] reported that the augmentation of fluid characterization by splitting plus fractions of fluid composition did not have a significant impact on the compositional gradings of both hydrocarbons and non-hydrocarbons in a given system. However, it is understood that GOC prediction from CGS is sensitive to the quality and representativeness of the underlying PVT dataset.…”

Unconditionally stable, efficient and robust numerical simulation of isothermal compositional grading by gravity

“…Many other scientists have studied many other factors that lead to the composition of petroleum fluids in subsurface circumstances including: thermal diffusion by Dougherty and Drickamer in 1955 [6], asphaltene precipitation by Riemens et al in 1988 [48], capillary forces by Lee in 1989 in [27] and Wheaton in 1991 [54], biodegradation by Temeng et al in 1998 [53], genesis by Smalley and England in 1992 [51], natural convection by Ghorayeb and Firoozabadi in [12], unsteady flux of a water aquifer partly contacting a reservoir by Hoier and Whitson in 2001 [16], reservoir compartmentalization by Elshahawi et al in 2005 [7], and incomplete hydrocarbon migration by Gibson et al in 2006 [14]. Enormous research in this area is still active (see [5,18,26,30,38,39,41,42,52] and references therein).…”