%0 Journal Article
%T A Novel Method for Improving Water Injectivity in Tight Sandstone Reservoirs
%A Mohamad Yousef Alklih
%A Bisweswar Ghosh
%A Emad Waleed Al-Shalabi
%J Journal of Petroleum Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/864624
%X Applicability of electrokinetic effect in improving water injectivity in tight sandstone is studied. DC potential and injection rate are varied for optimization and determination of their individual impact on clay discharge and movement. The liberated clays were characterized through size exclusion microfiltration and ICP-MS analysis. Real time temperature and pH monitoring were also informative. Results showed that severalfold (up to 152%) apparent increase of core permeability could be achieved. Some of the experiments were more efficient in terms of dislodgement of clays and enhanced stimulation which is supported by produced brines analysis with higher concentration of clay element. The results also showed larger quantity of clays in the produced brine in the initial periods of water injection followed by stabilization of differential pressure and electrical current, implying that the stimulation effect stops when the higher voltage gradient and flow rates are no more able to dislodge remaining clays. Additionally, fluid temperature measurement showed an increasing trend with the injection time and direct proportionality with the applied voltage. The basic theory behind this stimulation effect is predicted to be the colloidal movement of pore lining clays that results in widening of pore throats and/or opening new flow paths. 1. Introduction In general, the three phases of petroleum recovery processes are primary, secondary, and tertiary oil recovery. The primary recovery phase is mainly driven by the natural energy present in the reservoir due to dissolved solution gas pressure, pressure from the overlain gas cap, or the pressure from an active aquifer below the oil zone. In most cases, the natural driving mechanism is a relatively inefficient process and results in a low overall oil recovery [1]. The lack of sufficient and consistent natural driving energy is compensated by supplementing with injection of water or gas (or a combination of both) which is the initiation of the secondary recovery phase. Due to several technoeconomic factors, the most widespread secondary oil recovery process responsible for most of worldĄŻs oil production is the waterflood recovery [2]. Nevertheless, water injection may be associated with numerous hurdles related to fluid incompatibility, reservoir heterogeneity, early breakthrough through thief zones, permeability damage due to suspended particles, and clay swelling. Poor water injectivity is one of the problems often encountered especially in tight formations [3]. This problem may further aggravate, when swelling
%U http://www.hindawi.com/journals/jpe/2014/864624/