Study On The Evaluation Method Of Anti-water Blocking Agent

Low permeability reservoirs are widely distributed in China.However,water blocking damage is severe and seriously impacts the efficient exploitation of the reservoirs.Therefore,it is significant to study the mechanism and influence factors of the water blocking effect,and to establish a method to evaluate the water blocking for protecting the hydrocarbon reservoir.Establishing the evaluation method for anti-water blocking agent is the base of the water blocking prevention and reasonable application of removal measures.The key point of the evaluation is to demonstrate the changes of water saturation in the process of water blocking damage and anti-water blocking agent treatment.Through analyzing the repeatability and complexity of laboratory water saturation in cores establishment method,the simplified treatment method for establishing the water saturation of reservoir characteristics of the initial state,water blocking damage and anti-water blocking agent treatment was proposed.And then,the evaluation procedures were designed and achieved by core forward flooding and reverse injection according to the enter direction of related fluids into the formation.The experimental results shows that there are differences for the permeability recovered percentage of various anti-water blocking agents in cores with basically the same damage extent,which indicates that the designed standardized method is effective for the anti-water blocking agent evaluation.