Research On Formation Protection Of Well Completion For The Key Blocks In Dagang Oilfield

Because of low permeability, high shale content and grains of minerals but tiny pore throat radius, the serious formation damage is prominent in Dagang Oilfield. Although some achievements have been got in recent years, it still lacks a mature and effective system and the uniform understanding about formation damage in the completion process for low permeability reservoirs. It's meaningful that the basic laboratory of formation protection and the completion application research have been researched aimed at characteristics of the reservoir, for example, it's with low permeability and high salinity, contents of both clay and colloidal bitumen are high.Be given priority to the features of researched blocks, received with formation protection for complementary. It can make each chapter to be independent but a seamless organic whole. On the one hand, it will be of great value to increase the effect of development and economic benefit for low permeable oil fields. On the other hand, it will be served as a reference for similar field development effectively. According to the relevant literature and field investigation in Dagang Oilfield, the layer features, physical properties and rock mechanics parameters have been measured. Through sensitivity analysis and mechanism of formation damage the paper made an initial draft for formation protection of well completion. The laboratory evaluation integrated the supporting measures of formation protection. Based on a strong inhibitor NTW-1, it researched free solid perforation fluid named SKY-1 and SKY-2.The performance evaluation results showed that the permeability recovery rates have been more than 90%. According to the theoretical analysis on protecting formation perforation completion, the right value of underbalance perforating was calculated respectively. Enhanced perforation methods were studied on the basis of different sensitivity and degree of sand production. Besides, the slotted liner and gravel packing sand control have been researched. The sanding prediction was established by using logging information. Furthermore the research of completion manner was optimized. The test results indicated that they can reach the expected objects.