Cause Analysis and Treatment Measures for the Overload of the Screw Pump in Weak Alkali Ternary Drive

Block T is a weak alkali ternary drive development block in Sanan Oilfield. After injecting ternary fluid 0.21pv into the block, 23 screw pump wells in the block, successively appeared overloaded and stuck pump phenomenon, which seriously affected the time rate of the block. In order to solve the problem of weak alkali ternary drive screw pump non-adaptation, through the 23 overload, stuck pump screw pump wells for force analysis, combined with the ternary driving agent injection after the block of each parameter changes in the analysis, to determine the formation of liquid supply is insufficient, the stator rubber thermal expansion and dissolution, scaling, and other factors is the weak alkali ternary drive screw pump non-adaptation of the main controlling factors. Based on the analysis results, the block formulated corresponding measures such as dynamic decoupling method, optimizing the reasonable pumping and drawing system of screw pumps, designing efficient wax-cleaning tubing structure, and applying two-stage dynamic wax-cleaning method, which effectively solved the problem of maladaptation of the wellbore environment and conventional screw pumps for oil recovery and extended the checking and pumping cycle of the weak alkali ternary screw pump wells, which has an important significance for the design of the oilfield's late oil recovery plan and the timely management of two-rate reduction and production improvement work.