The Research On Subtle Reservoir Of The Dawangzhuang Area In The Raoyang Sag

The Dawangzhuang area is located in the mid-southern district of Raoyang Sag’s centraluplift belt section, among Hejian, Suning,Wobei and other source depressions, holding two sets ofhigh-quality source assemblages-Esx3and Es1。With a complex tectonic structure, this area hasbeen affected by buried hill basements, formed multiple large scale right arc fault step belts,which spread to periphery divergence，accordingly generated the main oil and gas supplypassage in the Dawangzhuang area。The oblique relationship between two major source (fromthe southwest, west direction) and fracture system，ensure that this area become a favorablesubtle reservoir development region。Although this area has complex structure, seismic data of low-quality，we has transformedtraditional research ideas，took advantage of low amplitude structure formed by the differentialcompaction，kept on searching for profitable reservoir development and subtle reservoir area。There are four main aspects of related works as bellow：Firstly-the analysis of mechanism andperformance of differential rock compaction。The differential compaction is divided into fourstages--fast compaction，steady compaction， accelerated compaction, low-speed compaction。By analyzing the control effect of compaction of muddy，sandy sediment on oil and gas, relatedscientific research has been pointed out that characteristics of differential compaction in theDawangzhuang area are low amplitude，micro amplitude appearance。Secondly-Thereconstruction of tectonic and sedimentary systems of this region，which has broken the pastsimple interpretation standard about reflection section practice of structure，carried outmultilayer structure interpretation with regard to the main longitudinal oil-bearing formation of Edand Es1，which provides a reliable basis for tectonic layer research，improve the accuracy ofgeological map to10m interval value，detailed characterized level change of structure,highligted the identification of low amplitude，subtle amplitude structure。Sincecomprehensively practice of the sequence strati-graphy method is used in sedimentary，sequencestructure from Ed3to Es3segment has been revealed。Through effective utilization of detritalcomposition, heavy mineral，chemical element analysis，weight of mudstone color, coreobservation and seismic attribute analysis，Dawangzhuang area’s sedimentary environment isdetermined-Es1(Braided River Delta)，Ed3(Shallow Water Delta)。Thirdly-the analysis ofancient tectonic background，helped to define the development characteristics of Dawangzhuangarea,including an ancient valley belt，two slope development zone, three inherited trough area。Combined overall present tectonic information, analyzed favorable reservoir development area，preferred three main evaluation directions as a result。Last but not least-The classification anddissection of known oil reservoir in this area，in order to establish two kinds of subtle reservoiraccumulation model-“negative pale geomorphology control up dip pitchout lithologic trapmodel”，“river reservoir plugging flanking transformation lens lithologic trap model”。Based on those above work，Different sores must have desperate salves, in the north of theDawangzhuang area，27wells have been drilled successfully in total，with a increase oilreserves of2.99million tons，contributed to the overall evaluation、implementation of thisdistrict，therefore a new round of reserves and productivity growth peak has been accomplishedactually。...