An Experimental Study of Formation Damage Due to Asphaltene Deposition During Natural Depletion in One of Iranian Oil Reservoir

Asphaltene deposition is an issue that has received much attention since it has been shown to be the cause of major production challenges. Asphaltene precipitation can occur during primary depletion of highly under-saturated reservoirs or during hydrocarbon gas or CO2 injection for improved oil recovery. Numerous laboratory researches and oilfield reports have investigated the effect of asphaltene deposition and its remediation under dynamic flow on reservoir rock properties. All techniques available into proper it، have proven costly and not highly effective، so prevention is the best way to counteract the problem. Revelation of the deposition mechanisms and determination of the parameters they influence it are essential in order to devise reliable prevention strategies. In this work، an experimental effort is made to investigate the permeability impairment of core samples، under natural depletion conditions and identify the dominant deposition mechanisms. The main tools that applied to do these experiments are permeability calculation، analysis of asphaltene concentration and high pressure and high temperature viscometer. Experiment carried on sandstone rock type. In addition، the study provides the deposition mechanism changes during production and it is strong dependent of oil injection rate.