Chengbei 313 Study On Single Well Evaluation And Analysis Method In Bohai Bay Basin

The Bohai bay basin is a meso-cenozoic faulted basin developed from the north China platform.It is the area where most oil and gas are found in the sea,and large oil fields such as Shengli,Liaohe,Bohai and Huabei have been developed.The Chengbei uplift is a geological structure developed on the basis of Chengbei Qianshan in the bohai bay basin.Its tectonic form is influenced and controlled by the sedimentary basement and the Chengbei fault,and the paleogene strata drapes or overlapped on the Qianshan mountain,and its tectonic form is similar to that of the Qianshan mountain.The neogene overhangs the Paleogene.At the end of Yanshan movement,the Chengbei fault began to move violently,which had a great influence on the geological structure of this area.A series of secondary faults parallel to the main faults developed on both sides of the Chengbei fault,which cut the whole Chengbei structure into several small fault blocks.Due to the overburden or draping of the strata,the cutting and blocking of fault blocks,the lithology changes in the transverse direction,and the traps of various types in this area create conditions for the formation of Chengbei complex reservoirs.In this paper,Chengbei well 313,located in the shallow sea area to the north of dongying city,shandong province,is taken as the research object.The tectonic location is the Chengbei 313 fault block in the eastern Chengbei low uplift of the Chengning uplift in the Bohai bay basin.Chengbei 313 is a evaluation well with a designed depth of 5000m(from sea level).Target strata:Guantao formation,Dongying formation,Paleozoic,Archaean.Principle of completion:100m into the taigu boundary,30m at the bottom of the well without oil and gas display completion.The purpose of drilling is to understand the oil and gas bearing conditions of Neogene,Paleogene,lower Paleozoic and Archaean in Chengbei 313 block.This study will analyze the evaluation of Archean reservoir,lower Paleozoic reservoir,Dongying formation reservoir and upper member of Guantao formation reservoir.The reservoir conditions,oil source conditions,reservoir conditions,cap conditions and reservoir forming control factors were studied.The reservoir of the upper member of Guantao formation,Dongying formation,upper Paleozoic,and Archaean was evaluated as a good reservoir with a certain reservoir capacity.