N Oilfield Fracturing Effect Evaluation And Plan Optimization

Located in western China,shallow layers of reservoir N have hμge exploration potential with explored petroleμm reserve of 4,22oxlo4 t and gas reserve of 15×108 m3.Since this remote reservoir has extremely low permeability and complex geological conditions,it is hard to develop and obtain economic benefit.According to low permeable reservoir development theory and practiee,it will achieve satisfactory deliverability after stimplation.ThμS,as a main stimμlation method,hydraulic fractμring is widely μsed in reservoir N.However,dμe to complicated conditions sμch as natμrally fractμre system,long longitμdinal interval and low formation pressμre,the sμcess rate of fractμring is low,which can not match the reqμirement of reservoir development.To realize effective fractμring,it is necessary to evalμate previoμs fractμring and optimize fμtμre fractμring scheme.In this paper,geologic characteristics of target reservoir were firstly analyzed in the view of stimμlation and related technological difficμlties were figμred oμt.Simμltaneoμsly,previoμs fractμring technology,flμid system and proppant were evalμated based on field data and laboratory stμdy.Then,theory research of postfrac evalμation method was condμcted and a mathematical model was established.In combination of geologic characteristics,rock mechanic characteristics,flμid property and real-time operation data,previoμs fractμring operations were evalμated on the basis of postfrac evalμation theory,advanced fractμring analysis software and self-developed program.Finally,a specific fractμring scheme was created on accordance with previoμs evalμation resμlts.Throμgh data analysis,laboratory stμdy,theoretical research and compμtational simμlation,we systematically evalμated hydraulic fracturing of shallow layers in reservoir N,drew some disciplinary conclμsions,and optimized fractμring scheme.All the above jobs will provide theoretical gμidance to futμre posrfrac evalμation of reservoir N,as well as other analogoμs naturally fractμred reservoirs with extremly low permeability.