加砂方式对复杂裂缝内支撑剂运移铺置的影响

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中图分类号：TE357.12 文献标志码：A

Abstract：Thefracturing operations in unconventional reservoirs in North America have shownthatthetwosanding methods， namely constantsand concentrationand stepped sand concentration，yield similar productionresults.The former method has advantages inreducingoperational dificultiesandrisks，as wellassaving theusageofhigh-viscosityfluids.However，currentlythere isalackof quantitative evaluationonthe diffrences inproppant placement efectsof thetwosanding methods underdifferentconditions，and thereisalackof theoretical supportforthelargescaleapplicationoftheconstantsandconcentration method.Inthisstudy，usingalarge-scalevisual particle transport testing equipment with rough fracture walsand branching fractures of diffrent angles，a setofcomparative experiments wasconducted with constantsanding and stepped sanding underdifferentoperating parameters.Theresults indicatethatthereisgenerallylitlediferenceinthe mophologyof proppant placement between the two sanding methods inboth the main fracture and branch fractures，withconstant sanding showingaslightadvantageinflingthedistalendofthemainfractureandthefar-wellbranch fractures.As thesandconcentrationincreases，thediferenceinsandbank morphologybetweenthetwosanding methods gradualldecreases，withadifference of 15.6% in sandbank height between the two methods at a sand concentration of 10% ，and a difference of 3.2% ata sand concentration of 20% . As the proportion of high sand concentration stages decreases，the difference in sandbank morphologywiththeconstantsandingalsodecreases，andthelengthof thesandbank graduallyincreases.Additionall，varying theparticlesize，density，and viscosityofthefracturingfluidcanalsoreducethediferencesbetweenthetwosanding methods.

Keywords：proppant transport；sand adition method;constantsand addition； stepped sand adition；complex fractures

在常规储层压裂中，常用高黏度压裂液以砂比阶梯升高的加砂方式（阶梯加砂）施工，利用高黏液较强的携砂性，形成导流能力由远井到近井逐渐增加的支撑裂缝[1-5]。（剩余15270字）