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A Study On Reservoir Characteristics And Elaborate Description, Lao 451 Block, Laohekou Oil Field

Posted on:2006-01-27Degree:DoctorType:Dissertation
Country:ChinaCandidate:M C MiaoFull Text:PDF
GTID:1100360155464463Subject:Structural geology
Abstract/Summary:PDF Full Text Request
The Lao 451 block of Laohekou oil field lies within the Gudao area, Dongying city, Shandong province, and tectonically situated on the middle part of north slope of Chenzikou uplift, Jiyang depression, Bohaiwan basin. It is a tectonic-lithology reservoir mainly concentrated in the Sha II and III formation of Paleogene. Launched into production in 1994, the first two wells, Lao 45 and 451, may yield industrial output and contrasted with the Lao 451-X1, L451-2 and L451-3 drilled in 1999, all of which are futile though geographically contiguous and the same in geological background and tectonic conditions with the Lao 45 and Lao 451. It indicates that the reservoir and residual oil are distributed extremely abnormal, and therefore resulting in the highly uncertainty in the exploration and development.In this thesis, the Sha II and III formation of Lao 451 are elaborately studied by means of mineralogy, lithology and sedimentology, and so as to constructing the sequence framework containing Sha II, III and Sha I to the Dongying formation on the basis of sequence formation study. According to the study above, the sequence framework may be subcategorized into 5 types, that is, steep slope, gentle slope, high horst, deep low-lying and alluvial type. It is revealed that, the sand bedding underlying the S1 is the shore bar deposition during the lacustrine transgression with wide lateral distribution, and the favorable reservoir in this area; the Sha II and III are underwater alluvial fan deposited during periodical progradation and characterized in reservoir by silt and conglomerate bedding overlying the Sha III formation, and mainly distributed on the hanging wall of east Lao 451 fault; the conglomerate, gravel and silt of Sha II formation are mainly distributed in two areas, that is, the area from the Lao X452 well to the X1 well, Zhuang 106-14-7 well to the Lao 451 well and the 106-14-10 area.The pore structure of the Sha II and III formation are systematically studied and revealed that the pore of the Sha II and III formation is mainly vugular-solution intergranular pore, vugular-solution intergranular pore and vugular-solution infilling inter-pore, and intergranular pore secondarily. The pore throat is mainly pore-shrinking and contraction type, and the pore structure may be divided into three types: U type, characterized by high porosity, high permeability and wide pore throat; Ib type, characterized by relatively high porosity and permeability and wide pore throat; IIa type, characterized by low permeability, medium pore throat lower than two types above. The residual oil is mainly controlled by the micro-facies, reservoir parameter and micro-features, all of which drive the residual oil to the positive rhythm sand bedding overlying the Sha II foramation and the mid-fan sand bedding of the Sha III formation, which are all favorable area for the subsequent progressive exploration.It is revealed that, there are 10 faults in the Lao 451 block, of which the east 1 fault of the Lao 451 well, south fault of the Lao 451 well and south fault of the Lao 45 well dominate the hydrocarbon migration, and the migrating channel is mainly sand bedding and relative fault. The east fault of the Lao 451 well works as the block for the hydrocarbon accumulation and plays a key role in the reservoir formation.Based on the geological study and the secondary logging-interpretation on tens of well, study on formation conditions, controlling factors, accumulation feature and distribution characteristics of residual oil in the Lao 451 block constrained by seismic inversion, the disciplinary knowledge of residual oil are generalized and may be of directive significance and practical value for the subsequent progressive exploration and development of the Lao 451 block.
Keywords/Search Tags:Lao 451 Block, Shahejie formation, reservoir, residual oil, reservoir description
PDF Full Text Request
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