SPE-176728-MS Combining Conformance Treatment with Mobility Control Improves Oil Sweep Efficiency in Non-Cross Flow Heterogeneous Reservoirs Abdulmohsin Imqam, Baojun Bai, and Mingzhen Wei, Missouri University of Science and Technology Copyright 2015, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Russian Petroleum Technology Conference held in Moscow, Russia, 26 –28 October 2015. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract On water flooding process, water preferential flow through high permeability, fractures, and large channels; cause a large amount of recycling of water without much benefit to oil production. Preformed particle gels (PPGs) have drawn more attention to reduce the fluid flow in these large opening features and to improve macroscopic oil efficiency. In spite of the successful applications of using PPGs in plugging such large features, there is still need to combine PPGs with other technology to produce more oil from the low permeable rich zones. The ultimate purpose of this study is to investigate the effectiveness of combining conformance control treatment using PPGs with mobility control using polymer to enhance oil recovery from both swept and un-swept oil zones. PPGs was injected into large permeability zones to reduce their permeability while polymer injected after gel to further increase oil recovery from the low permeability zones. Two separate parallel tubes packed with different sand grain sizes were designed to emulate the case when there is non-cross flow heterogenity between the low and the high permeability layers in the reservoir. Experiments were designed to examine the effect of permeability contrast ratio on the performance of coupling PPG and polymer to increase oil recovery. The results show a significant increase in oil recovery from both low and high permeability cores after performing polymer flooding right away after gel treatment. The oil recovery incremental was varied and strongly dependent on permeability contrast ratios. PPGs improved oil sweep efficiency significantly when the core permeability layers became more heterogeneous. Injection profile was improved after the PPG treatment, thus oil recovery from the low permeability cores was increased significantly. Introduction Water flooding is often associated with problems caused by unwanted water production. This unwanted water production becomes more severe when the reservoir becomes more mature. Reservoir heterogeneity is the single most important reason for low oil recovery and excess water production. Most oilfields are characterized by complex geological conditions and high permeability contrast inside reservoirs. Many of them have been hydraulically-fractured, intentionally or unintentionally, or have been channeled due to mineral dissolution and production during water flooding. The heterogeneity caused large quantities of oil unrecovered during water flooding processes. Therefore, improving the reservoir’s sweep efficiency is an