近年,不断发现新的火成岩油气藏,其勘探潜力巨大.但是火成岩岩性复杂,储层多为溶蚀孔洞—裂缝双重孔隙介质的强烈非均质储层,其岩性测井识别与储层测井评价都非常困难.为此,以准噶尔盆地东部石炭系火成岩为例:①针对岩性复杂多样,岩性识别敏感参数不清的问题,利用主成分分析方法确定该区块的火成岩岩性敏感曲线为密度、电阻率和自然伽马,并在此基础上建立了三维岩性识别图版;②针对物性解释精度低,基质孔隙度计算采用岩心刻度测井曲线的方法,分岩性建立了物性解释模型;③采用建立成像测井与双侧向测井相关性的方法来表征裂缝孔隙度.结果表明:①三维岩性图版比二维图版增加1个参数,更适合复杂的火成岩岩性解释;②经过岩心刻度分不同岩性建模计算的基质孔隙度符合储量计算的精度要求;③裂缝孔隙度的计算结果表明裂缝发育与岩性有着密切关系,储层主要发育在裂缝孔隙度较高的角砾凝灰岩和火山角砾岩中,安山岩岩性致密,但裂缝较发育,可作为潜力储层.

The reservoir characteristics including lithology,lithofacies,pore type of the Carboniferous volcanic rocks in the 6th,the 7th and the 9th areas of Karamay oil field are analyzed based upon core observation,thin section identification,scanning electron microscope analysis and well logging interpretation.The reservoir pore space types,relationship between the reservoir spaces and flowing passageway and main parameters affecting the reservoir quality are also studied.The results indicate that the major rocks are lava which includes basalt and andesite,pyroclastics and pyroclastic sedimentary which includes volcanic breccia,tuff and sedimentary tuff.Three types of reservoir spaces including vesicles,pores and fractures can be classified based on the pore structures,and the primary and secondary pores can be identified based upon origin.The major controlling parameters for reservoir quality are petrology,lithofacies and tectonic action as well as weathering and leaching processes.

The rocks of 6th,7th and 9th zone of Karamay Oilfield are mainly composed of andesite,basalt,miscellaneous sandstones,tuff and volcanic breccia.By core analysis and FMI/EMI imaging logging interpretation,it is concluded that fractures are developed in all lithologic reservoirs of carboniferous,developments of the fractures are characteristic of multi-stage and multi-orientation,fractures in volcanic breccia and tuff are more abundant than that of basalt and andesite.Production and well test showed that various lithotypes of carboniferous are all possible to be good reservoirs.In volcanic rock,its porous types are mainly of fracture and matrix dissolved pore,its main reservoir mode is fracture-directly-connecting-fracture type,and fracture-indirectly-connecting-pore/fracture type.The reservoirs of carboniferous in 6th,7th and 9th zone are characteristic of double-medium fracture-pore reservoir with low-porosity,low-permeability,and high-heterogenity.The reservoir distribution is controlled by weathered layer and fracture growth.Having integrated data of core observation,rock section analysis,logging analysis,production and well test,summarized are the characteristics and identification methods of three types of oil pay zones with low,middling and high-resistivity volcanic rocks reservoir of carboniferous in Karamay Oilfield.

J_1S~(2-2) in Pen5 well block in Mosuowan Oil Field is a condensate gas reservoir with oil ring.Gas zones distribute uniformly on the top of the reservoir.They have a uniform bottom boundary(-3 860m).Below-3 860m,Well M103,M104,M106 and P5 in the north of the structure are oil zones,while M101,M102 and M105 in the south are water zones.No apparent geologic limit is found between oil and water wells.Study on seismic profile,sedimentary phase and reservoir structure shows that J_1S~(2-2) appears as imbricate progradation structure of single sandbody formed from distributive channels sedimented barriers.Study on sealing characteristics of barriers shows that,barriers cannot seal gas zones,but can seal oil zones.Thus the controlling effect of J_1S~(2-2) reservoir is determined.The gas cap is structural gas reservoir,and oil ring is lithologic-structural reservoir.

On the basis of analysis and study on core data, logging curves, drilling and seismic data gathered from 5 evaluation wells( Well Mo-101, Well Mo-102, Well Mo-103, Well Mo-104, Well Mo-105) , well Pen-5 and Pen 6, we obtained the petrological features of of J1s 22. It is considered that reservoirs are medium-fine litharenite, unequigranular litharenite with little fine litharenite, the target zone consists of subaqueous channel,subaqueous natural levee,distributary mouth bar and front sand sheet with sedimentary facies of delta front, and then sedimentary sequence and distribution are described in this paper. Through a systematic diagenesis analysis of J1s 22. reservoir, diagenesis type, diagenesis sequence and their stage can be classified. The author points out that compaction, clay mineral, sensitivity and Soft Lithic Fragment are main factors influencing reservoir.