Speaker at Oil, Gas and Petroleum Engineering 2022 - Md Saiful Islam
Dhofar University, Oman
Title : The Role of Capillary Continuity on EOR of a Fractured Reservoir

Abstract:

All hydrocarbon reservoirs are fractured to some extent. Due to the structural and petrophysical complexity of fractures, very special flow simulation modeling (e.g., dual porosity modeling) is indispensable for fractured reservoirs if the fractures are interconnected and build the primary flow path between injection and producing wells. There are two different recovery mechanisms are usually used to simulate the fractured reservoirs, for example, water-oil-imbibition (WOI) and gas-oil gravity drainage (GOGD). Ideally, oil is displaced by water for WOI and by gas for GOGD mechanism for naturally fractured reservoir. Relative permeability of oil-gas or oil-water, and capillary pressure curves have a great influence on enhanced oil recovery (EOR) for WOI or GODG system in naturally fractured reservoirs. The principal endeavor of this work is to investigate the influence of capillary continuity (i.e., the connection between two consecutive matrix blocks) and matrix block’s height on EOR by applying WOI and GOGD recovery mechanism for naturally fractured reservoirs. Therefore, the task is to create a certain numbers of dual porosity models to investigate relations between different geometric configurations of matrixfracture system on EOR. In the dual porosity modeling, there is a fracture between two matrixes, every two consecutive matrixes are considered with different contact area (e.g., 0%, 5%, 25%, 75% and 100%), referred as the capillary continuity. In WOI or GOGD displacement process, the major role of the fractures is to supply sufficient volumes of water or gas to the matrix blocks to maintain the displacement process. The fractures are initially 100% saturated with water or gas for the cases investigated.                   

Audience Take Away:             

  • The endeavor of this study is to familiarize the audience about the different effects of water and gas injection in a natural fractured reservoir. The task was to create a certain numbers of simulation models to investigate relations between different geometric configurations of matrix-fracture system and oil recovery by GOGD and WOI mechanism.
  • In water-oil case, most of the oil is produced @ water breakthrough time by spontaneous imbibitions and less oil is produced after water breakthrough by forced imbibitions. There is no significant influence of different stacks of matrix blocks, different contact area between matrix and fractures, different water injection rate on oil recovery.
  • In oil-gas case capillary continuity between matrix blocks plays important role in oil recovery process. Existence of contact area of just 5% can improve oil recovery significantly by additional 4 – 11 % (depending of the number of blocks in stack).
  • If the capillary continuity between blocks exists, increasing contact area does not have big impact of final oil recovery.
  • The increasing height of the matrix block results in greater oil recovery.
  • The rate of water/gas injection does not have any significant impact on final oil recovery.

Biography:

Dr. Md Saiful Islam is an Assistant Professor in the Department of Mechanical Engineering, Dhofar University, Oman. Previously, he worked for ca. 7 years as Reservoir Engineer for Bangladesh Petroleum Exploration and International Conference on Oil, Gas and Petroleum Engineering Conference (IOGP 2022) Production Company. His research interests include reservoir modeling, upscaling, fault/fracture modeling, geomechanical modeling, EOR, ML. He holds a PhD degree in Geological Sciences (Major: Reservoir Modeling) from University College Dublin, an MSc degree in Petroleum Engineering from Norwegian University of Science and Technology, and a BSc degree in Mechanical Engineering from Bangladesh University of Engineering and Technology. He is an active member of SPE, PSAAPG and EAGE.

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