Blockage Removing And Wormhole Enlarging Effects Of The Acid Combustion Products Of Gas Generator In Near Wellbore Zone

At present,most of the oil wells have been in a state of low yield,which is mainly due to the oil deposits that clog the oil flow channel.Traditional acidification technology is currently the most common plug removal process,but there is serious secondary pollution and waste of resources.Consequently,developing new acidification process is imminent.On one hand,the acidification process of Gas Generator can effectively substitute traditional process by removing the mineral deposits near down-hole zones.On the other hand,this process can force the acid liquor permeate into oil reservoir and intensify the reaction to create pores under high pressure,so it will achieve the purpose of oil increasing in two ways.The Gas Generator formula contains large amounts of acidic components,whose combustion products have a certain concentration of acid.So different Gas Generator can generate different amount and different types of acid.This paper calculate the theoretical acid production of the existing formula of Gas Generator,and conduct pH measurement and ion analysis for the acid in bench test.The experimental results show that the type of acid is monotonous and the production is insufficient under the existing formula.So we need add other types of anions to the new formula of Gas Generator to increase the capacity of acid products.To design the formula of Gas Generator to suit for more reservoirs,we need to clear the minimum acid consumption required by different type of reservoirs.Based on the data of solvency and others,we firstly establish the minimum acid model of plug removal and the minimum acid model of wormholes,through which we measure the impacts of strata porosity,action range,the reactant concentration and acid concentration on the minimum acid consumption.The results are consistent with the actual production process.Thus,the minimum acid model is suitable for calculating the acid consumption for different type of reservoirs.Generating wormhole has a higher requirement for acid-rock reaction,which must be controlled by the diffusion process,and a maximum convection rate will be necessary in the acid-rock reaction.To verify whether the Gas generator can generate wormholes under high-temperature high-pressure environments after combustion,the wormholes thermodynamic model is built to test the existing Gas Generator formula and domestic oilfield preliminarily.The results show that Gas Generator generate can wormholes under the conditions of combustion.Furthermore,we examined the effect of the changes in some conditions during the reaction process,including temperature,acid concentration,reaction order,pressure,operating distance and other conditions.The results of examination consistent with the actual production process.Therefore,the wormholes thermodynamic model is available to verify whether the different type of Gas Generator formulas can generate wormhole in different reservoirs.