取心工具或打捞篮下入井底后,先要进行正循环以清洗内筒,后要求投球堵孔侧循环进行取心或打捞。而取心或打捞又要求在下钻时带回压凡尔。带回压凡尔就投不了球,要投球就不能带回压凡尔。为此笔者设计了用变排量控制投球的6″阻流式投球接头,解决了带回压凡尔也能投球的问题。经现场使用,效果良好。 Coring tools or salvage baskets into the bottom of the well, the first positive cycle to clean the inner cylinder, after the pit asked blocking the ball side of the loop for coring or salvage. The coring or salvage also asked to bring back pressure when drilling. Bring back pressure Versail can not cast the ball, can not bring the ball back to pressure Versailles. To this end, I designed a variable displacement control of the pitching 6 "choke ball joint, to solve the problem brought back pressure Versail can also be pitched by the scene, the effect is good.