Technology for Improving Development Effectiveness of Asphaltene Precipitated Carbonate Oilfield: A Case Study of B Oilfield, Middle East

B Oilfield is a typical thick porous carbonate reservoir in Middle East. 40 years of depleted development have led to a significant decrease in formation pressure, severe asphaltene precipitation, and oil production decline. In order to improve development effectiveness, research has been conducted on reservoir characteristics analysis, water injection mode optimization, technical strategy formulation, mechanism of asphalt precipitation, and stimulation measures. It is shown that high-quality reservoirs are developed at the top of the reservoir, using a mode of peripheral water injection and internal pattern injection, injection in bottom layer and production in top layer, to restore formation pressure while avoiding rapid water breakthrough. Based on the pressure of asphalt precipitation and the demand for liquid increasing, technical measures are proposed to maintain the formation pressure level at 80% of the original formation pressure, strengthen water injection at the edges, and mildly water injection internally. By analyzing the sedimentary conditions of carbonate asphaltene, an integrated stimulation technology combining organic solvent soaking and acidizing is proposed, which can effectively remove well pollution and restore oil productivity. By these technologies, the actual practice in B Oilfield had shown that the formation pressure recovered quickly, and the oil natural decline rate is reduced by 7.2%, significantly improving the development effect.