The Western Tabei Uplift is one of the largest first-level structural units in the Tarim Basin with great potential for oil and gas resources. Previous studies have established sedimentary provenance of the upper and lower strata in the unconformity of the Cretaceous Bashijiqike Formation and Paleogene Kumugeliemu Group in the Western Tabei Uplift. However, little attention has been paid to the light-colored, white-ish sandstone at the interface of this unconformity, whose sedimentary provenance remains to be investigated. Based on morphology, U-Pb age and trace element analyses of detrital zircon, our study reveals five age peaks in detrital zircon age distribution, -300 Ma, -420 Ma, -820 Ma, -1.8-1.9 Ga, -2.4 Ga. Potential sources of white sandstone include the Quruqtagh region to the east (E-source), the South Tianshan to the north (N-source), the west of East Tianshan and the north part of Quruqtagh to the north-east (NE-source). Their detrital zircon U-Pb age information is collected and compared with those from the white sandstone. The detrital zircon age comparison demonstrates that the Esource is the primary sedimentary source area for the white sandstone, the N-source may also provide some additional sediments. The detrital zircon age pattern also indicates that the origin of the NE-source is probably supplied by both the E-source and N-source together. Our finding could shed new light on the provenance and sedimentary model of Cretaceous-Paleogene white sandstone member in the Western Tabei Uplift and provide a theoretical basis for further exploration of lithological oil reservoirs in this section.

YM32下古生界潜山油气藏是受断裂控制的低幅度油气藏,油气运聚复杂.结合新钻井的地球化学分析数据,对研究区油气藏油气运移规律进行剖析.依据YM32下古生界潜山气田藏的原油及抽体物样品中的饱和烃的烷烃、甾藿烷,芳烃的萘与菲、烷基二苯并噻吩、三芳甾烷等生物标志化合物进行系统分析,优选油气示踪参数,并归一化,结合族组分分析结果,形成了油气运移示踪二步法.综合研究发现,YM32下古生界潜山油气藏有YM342-YM343和YM322两个油气充注点,以及YM342-YM 343→YM 34-1H→YM 32、YM342-YM343→YM34-7H→YM33、YM342-YM343→YM37-YM35,以及YM322→YM321→YM32共4条油气运移路径,并在YM342-YM343→YM37-YM35油气运移路径上,发现2个资源量超过1.00×106t的潜力圈闭.单参数与油气运移示踪二步法都可以反映油气运移路径,而后者具有全面、直观、准确地表征油气运移路径的特点.

During the study of oil and gas geochemistry, analysis of big data must be experienced, and there are some abnormal values in tremendous amount data, which will affect the analysis results of oil and gas migration. On the basis of geochemical big data of YM32 buried hill reservoirs in Tarim Basin, the mean value and standard deviation of hydrocarbon compound parameters reflecting the direction of hydrocarbon migration in the samples are analyzed, and the outliers, which less than X̅ −2D and great than X̅ +2D, are excluded. According to the content of saturated hydrocarbon and aromatics, the hydrocar bon migration factors are calculated and analyzed, and a three-step method of hydrocarbon migration tracer is formed. It is inferred that there are two oil and gas filling points of YM342-YM343 and YM50 in the YM32 buried hill reservoir, as well as four migration paths of YM342-YM343 to YM34, YM342-YM343 to YM37 to YM35, YM342-YM343 to YM33, and YM50 to YM321. The method can be used for reference in the evaluation of oil and gas reservoirs and in the search of remaining oil enrichment areas.

The oil and gas resource of YM34 Silurian accumulations is abundant, with a great potential for exploration and development. However, there is less research on the hydrocarbon migration mechanism because of complex structure and few data in the YM34 Silurian accumulations. By using gas chromatography-mass spectrometry (GC/MS) technique, the group composition, and biomarkers, including N-alkanes, isoparaffin and steroid hopane from saturated hydrocarbon and methyl phenanthrene, alkyl dibenzothiophene (DBTs) and triaromatic steroid(TAS) from aromatic hydrocarbons, which from 108 samples in 20 representative wells of YM34 Silurian accumulations and its peripheral reservoirs, are systematically analyzed and studied. The results indicate that: (1) along direction of hydrocarbon migration, the MPR, F1, and F2 increase, but the MPI1 decreases, which is caused by the relative larger amount of phenanthrene in the samples; (2) during oil and gas migration, the geochromatography effect of triaromatic steroid will happen. Along the migration pathway, the value of C27(20R)/C28(20R) increases; (3) the hydrocarbon charging point of YM34 Silurian accumulations is in the western YM342 and YM343 wells, and oil and gas are charged from west to east, which has certain guiding significance for progressive evaluation and development geological modeling of YM34 Silurian accumulations.

The oil and gas abundance in YM34 structural belt, so it is potential in exploration and development. However, due to complex geological structure, it is difficult to further study in hydrocarbon migration and accumulation mechanism. Based on structural characteristics, crude property, group component characteristics, saturated hydrocarbon chromatography-mass spectrometry (GC/MS), analysis on the alkanes, steranes and terpanes of biomarkers of crude oil in YM32 buried-hill hydrocarbon reservoirs indicated that YM34 Silurian reservoir forming zonation are obviously as follows: 1)The western reservoir in wells YM342,YM343 as the representative of the "three low and one high" features, namely, low density and viscosity, low ratio of saturated/aromatic hydrocarbon, followed by high fraction saturated and aromatic hydrocarbon. 2) Oil and gas migration in YM34 Silurian reservoir is from the west to the East, accumulation period of the West was later than the East. 3) The results of oil-source correlation from source rocks in the Kuqa depression indicated that source rock of the west in YM34 Silurian reservoir is superiority to the Triassic lacustrine mudstone, then that of the east is of Jurassic coal mudstone.

利用泥岩断层泥比值法(简称SGR法)可估算断层可支持最大烃柱高度.在塔里木盆地英买力地区首次通过改进泥岩断层泥比计算公式,结合油藏和地震资料,计算了英买34井区油藏油柱高度标定参数d和圈闭烃柱高度h,确定了有效圈闭范围,为进行钻前定量评价、降低勘探风险提供依据.

Study on Mesozoic and Cenozoic extensional structure deformation is a weak part in Central Asian geological research. As one of the important Mesozoic and Cenozoic sedimentary basins, the research about Tarim basin has no exception. Some fine seismic interpretation shows that a large number of extensional tectonics which are composed of a set of small normal faults arise in Mesozoic and Cenozoic in northern Tarim basin. The small normal faults are clearly seen to array in en ethlon form, composing a series of fracture belts in planes, and their pattern in profile is a ladder and graben or horst. Based on their spatial distribution, structural styles, composite relations, the ages of growth strata, and genetic mechanism, the formation of normal faults can be divided into two phases: Jurassic-Early Cretaceous and Late Cretaceous-Neogene extensional tectonics. The former is a product of the stress releasing after the orogenic period of southern Tianshan, and the latter is caused by the escaping structures of Tarim basin towards east by south relative to South Tianshan, which were produced by the long distance effect of Himalayan collisional orogeny.

3D MOVE and 3D STRESS models are used to analyze the fault,fracture shape and distribution of buried hill of carbonate rocks in Lunnan area,including the stress mechanism,stability and slip vector of fault faces,the extension tendency,slip tendency and factors of seepage and leakage of fracture and fault faces.The reservoirs controlled by the fault and fractures are predicted,and the connection and stability of fractures are analyzed,in order to effectively guide exploration and development in the studied area.

Carbonate karst reservoir is the emphases of Tarim’s carbonate exploration. However, it is buried at a large depth, which results in weak seismic reflection signal and low S/N ratio. In addition, the karst reservoir contains great heterogeneity, so reservoir prediction is very difficult. Through many years of research and exploration, we have established a suite of comprehensive evaluation technology for carbonate karst reservoir using geophysical characteristics and a geological concept model, including a technique for reconstructing the paleogeomorphology of buried hills based on a sequence framework, seismic description of the karst reservoir, and strain variant analysis for fracture estimation. The evaluation technology has been successfully applied in the Tabei and Tazhong areas, and commercial production of oil and gas has been achieved. We show the application of this technology in the Lunguxi area in North Tarim in this paper.

碳酸盐岩岩溶型储层是塔里木盆地轮南地区重要的储集层.根据钻井揭示的岩溶型储层,对测井、地震响应以及地震各种属性的特征进行了标定、对比和归纳分析指出:碳酸盐岩岩溶的缝洞型储层,在测井上的响应特征主要为低伽玛、具有正幅度差异的双侧向低电阻率等特征;利用模型正演和岩溶精细标定技术,确定了碳酸盐岩岩溶缝洞型储层在潜山表面表现为弱振幅、弱连续、低速度、低频率的反射特征;而其内幕的缝洞系统则表现为,强振幅、低频率、低速度的杂乱反射特征;在地震属性上潜山表面岩溶型储层具有低相干、弱振幅、低阻抗等特征;而在潜山内幕则表现为低相干、强振幅、低阻抗的特征.

因地震分辨率的限制,根据速度谱计算出的层速度实质上是层间均方根速度,由此计算出的平均速度大于其实际值,同时也大于VSP平均速度.地震分辨率越低,速度谱计算出的平均速度误差越大.速度谱解释时漏读迭加速度同样会使平均速度计算值偏高,误差增大.文中指出,提高地震分辨率是提高速度谱计算速度精度的基础,研制高分辨速度谱,对速度谱计算出的层速度进行适当校正,细心解释速度谱,可提高速度计算精度.