Study On Reservoir Characteristics Of The Pre-khuff Formations In Block BC, Qatar

Though reading the wide range of literature and material of clastic reservoir research, atsame time, combined with the results of the previous researchers, we make full use of thedata of reservoir lithology, physical properties and logging to realize the purpose of studyingthe reservoir microscopic characteristics of Pre-Khuff series of strata on Qatar BC block.The reservoirs of Jauf group Jauf res. on Devonian and Unayzah group on Permian areclastic reservoirs, and the granularity of the latter is a little bigger than the former. There isillite as cementation content in the reservoirs, mainly, and a small amount of overgrowthquartz and iron dolomite. The reservoir of Jauf group Jauf res. has entered into the latediagenetic stage and the same to the segment S1, S2of the reservoir of Unayzah group,basicly. But, part of S1which is at high structure is still in middle diagenetic stage B period.The reservoir of Jauf groups is fine and close in whole, only Jauf res. develops a smallamount of dissolution pores. The pore of Unayzah group is relatively developed, especiallythe segment S2. This part has both primary pores and secondary porosity. Overall, the poresamong the grain make the largest contribution to the property of reservoir. The small throatpore and the poor sorting led to bad property in Jauf group D3B segment. Jauf res. section isbetter than Jauf group D3B segment in porosity and permeability. The segment S1ofUnayzah group is similar to D3B segment, but the physical property of the segment S2ofUnayzah group is outstanding. All in all, the reservoir of Jauf group and Unayzah group areboth low hole and permeability reservoirs, because of their poor property, especially the lowpermeability.The key factors to the availability of the reservoir of Pre-Khuff series of strata containreservoir physical foundation, diagenesis and micro cracks, etc. Referring to the prior standards, the reservoirs are divided into four classes on the basis of characteristics ofreservoir lithology, physical properties, diagenesis types and diagenetic facies.