Temporary Blocking Selective Water Shut Off And The Acidification Of The Integration Of Technology Research And Application

During the development of high permeability and interlayer heterogeneous sandstone reservoir, serious heterogeneity leads into the increasing interlayer conflict.one hand the high permeability layer produces much water, on the other hand the relative low permeablity layer is contaminated during development and the inner oil is hardly produced. According to the above situations and taking the contaminantion during water shutoff into account the dissertation put forward the temporary protective water shutoff and acidizing integrated technology. The dissertation involves the blow contents:I Accoding to the technology requirments for plugging agent, the dissertation has developed an underground polymerizing and crosslinking plugging agent, it bears the blow merits:good injectivity, larger strength and stonger acid resistance;II The dissertation has studied the damge to low permeability layer during the gelant general injection. It has analysed the below factors that influence on the damage degree, these factors involve interlayer permeability ratio, fluid viscosity ratio, resistance factor and residual resistance factor so on. The dissertation has discribed the selective injecting technology and at last according to the integrated techonology has put forward the temporary protecting technology.III Adopting a kind of suspending grain as the temporary plugging agent,with experiments we has gotten the optimum ratio between average pore diameter and grain diameter that can form bridge blimding. And by adopting the larger bridge blimding grain and smaller filling grain it can quikly form the compact temporary plugging under higher pressure, in the end the temporary plugging can be removed by the acidizing.IV Based on the formation characteristics and damage mechanism the dissertation has optimized acid system and corresponding additive system. It has selectted fluorboric acid as the main acid, sometimes in order to enhance the contamination corrosion we can adopt the mud acid and complex acid, at last with the coreflooding experiments we decide the hydrochloric acid and fluorboric acid as the applied acid system.V The dissertation studies the injecting technology of temporary plugging water shutoff and acidizing integrated technology, and it has analyzed the factors that affect injecting velocity and injecting intensity of plugging agent and acid agent. And based on the special reservoir situation it has recommended the injecting velocity and injecting intensity range of plugging and acid agent. The well shutoff time and acid reaction time are also recommended.