The Optimization And Realization Of Nagtative Pressure Spent Acid Disscharging And Plug Releasing Echnology In Water Injection Well Based On The Computer Control

In order to reduce secondary pollution, at the same time, to lengthen the term of treating validity, it's important for acid injection wells to make reacted acid flowback to ground surface after acidizing. At present, there are many methods of acid return being used in oilfields, but all of them have their disadvantages such as flowing back not thoroughly, lower adaptability, lower flowback speed, high cost and so on. Therefore, the author researched a new type, rapid, adaptable, and low-cost technology of acid return under negative pressure.The project is began with acid treating technology, studying the implementation lines of acid return under negative pressure, separately from throwing of acid-blocking plug, acid return, recoil, and fishing technology, so as to clear the course of its operation and the steps of the implementation. According to the needs of the entire process, the author designed acid-blocking plug, bottom hole switches, recoil valve, fishing tool and so on, and outlined the working principles and technical indicators of each tool.This thesis is based on the researching of jet pump, makes use of jet pump, working together with other matching flowback equipments to get the reacted acid out of target zones under negative pressures speedily and completely. Assistant flowback equipments such as break down tool, downhole switch valve, backsurge valve and fisher were all designed, their operational principle and technical description were given briefly in the article.In house tests and in-situ tests gave the proofs that this kind of equipments can make the reacted acid back to the ground effectively and efficiently. It's application has a wider prospects in oilfield production.