Temporary plugging and acidization method for multiple seams among sections of horizontal wells

Abstract

The invention provides a temporary plugging and acidization method for multiple seams among sections of horizontal wells. The temporary plugging and acidization method for the multiple seams among thesections of the horizontal wells comprises the following specific steps: 1) selecting a target well from the horizontal wells of which the daily fluid production rate is smaller than 2 cubic meters or the daily oil production rate is smaller than 1 ton; 2) performing shut-in pressure survey; 3) treating a shaft; 4) lowering a drilling rig to the corresponding position; and 5) performing pressuretest before acidization construction, and constructing after the pressure test is qualified, and connecting a plurality of acid tanks to an acid feeding pipeline synchronously. The method can achievethe purpose that the capacity of the horizontal wells with low capacity caused by results such as formation plugging and low stratum energy is recovered. An alternative well is subjected to pressure test first, and if the stratum energy of the alternative well is kept lower, the stratum energy is first supplemented, and then through temporary plugging and acidization, the sweep area is increased,and the permeability of a low permeability zone is increased, and the capacity of low-yield horizontal wells can be recovered.

Description

technical field [0001] The invention belongs to the technical field of repeated transformation of old oilfields, and in particular relates to a multi-fracture temporary plugging acidification method between horizontal well sections. Background technique [0002] At present, horizontal well development has become the main development method for low permeability oilfields. However, some horizontal wells also have prominent problems such as rapid production decline and rapid water cut rise. Repeated reconstruction of horizontal wells has become an important part of restoring oilfield productivity. [0003] There are two main means of repeated stimulation of horizontal wells in China: repeated fracturing of horizontal wells and repeated acidizing of horizontal wells. The horizontal well refracturing construction technology uses the fracturing vehicle to pump fracturing fluid and proppant into the horizontal section, which has high stimulation intensity and high operation effici...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the problem that the acid liquid preferentially enters the high-permeability zone in the existing method, and the low-permeability zone basically does not enter the acid, so the repeated reconstruction of the horizontal well is insufficient and the reconstruction effect is not good. The present invention provides a multi-fracture temporary plugging between horizontal well sections. In the acidizing method, the present invention injects a large amount of oil displacement fracturing fluid into the horizontal wells that have been produced for a period of time to supplement the formation energy; for the horizontal wells, the staged acidification is carried out, the target formation is more obvious, and the acid liquid enters the formation and the affected area is larger; Plugging acidification, blocking the high permeability zone, focusing on acidizing the low permeability zone, dredging the low permeability zone, can improve the oil flow channel of the remaining oil, and realize the production recovery of the low production horizontal well to the greatest extent