Research on Solutions of the Influences of High Pressure Repeating Packing Sand Control on Productivity

When the well with high-pressure packing sand control becomes invalid a relatively thick sand-gravel mixing zone will exist outside the casing. The mixing zone can hardly be cleared up in the process of later repeating sand control, so with the multiplicity of sand control increasing, the thickness of the mixing zone increases accordingly, which will do harm to the productivity of well. Aiming at this problem, the authors first analyzed the packing zone outside casing and then three optional solutions were given: fracturing packing sand control, casing external gravel packing zone acid pickling, and high-pressure variable diameter gravel packing technique. Especially, the authors proposed the technique of acid pickling of casing external gravel packing zone, and its technical ideas and main points were expounded for the first time; according to the Saucier method and the arch bridge theory, the authors analyzed the optimization of gravel size in the technique of high pressure variable diameter gravel pack...