Paleozoic Dolomite Gas Reservoirs In The Changqing Gas Field The Acidification Technical Experimental Design Model,

Acidizing was a very effective and economical well stimulation technique and was widely used in carbonate formation. Unfortunately, some technical problems urgent to be solved still exist, such as rapid acid reaction for carbonate rock, very short effective distance of acid penetration brings about much difficulty in its acidizing.This thesis principally researches the acidizing technology of Ordovician dolomite gas reservoir in the middle of Eerduosi basin. This thesis researched characteristics of the low-permeability dolomite formation and developed the suitable acid system by doing a lot of experiment because acid plays greatly important roles in well acidizing. The model of wormhole penetration was developed and the density of wormhole can be predicted through investigated a great deal of domestic and overseas literature and systematically analysis and contrast the existing model for carbonate acidizing. In addition, the method for calculating the distance of wormhole penetration and prediction gas well's productivity after acidizing were established by analyzed the key technology, the acid system which was suitable to the dolomite reservoir acidizing was optimized and selected, Based on theory of gas flow in rock, Considering the infection of startup pressure gradient, the estimate productivity formulae for gas well with low permeability were deduced.This thesis mainly achieve the following content:(1) Research the Ordovician dolomite reservoir and acid-rock reaction characteristics, analyzed gas well stimulation crucial technological factor.(2) Developed and estimated acid system for the formation by doing lots of experiment and mensurated the correlative acid-rock reaction parameters by applying the parallel plates reaction model.(3) Simulation the acid-rock reaction and observed the wormhole behavior in dolomite core .by doing a lot of experiment.(4) Established the model of wormhole and calculated the distance of penetration and density of wormhole.