Yang N.,China University of Petroleum - Beijing |
Wang G.,China University of Petroleum - Beijing |
Lai J.,China University of Petroleum - Beijing |
Li J.,China University of Petroleum - Beijing |
And 3 more authors.
Oil and Gas Geology | Year: 2013
The Lower Cretaceous Bashijiqike Formation in Dabei area of Tarim Basin is a typical fractured tight sandstone reservoir with dual porosity structure consisting of low porosity and permeability matrix and fractures. This kind of dual porosity structure results in complex gas-water contact in the reservoir. It is always difficult to evaluate the productivity of this kind of reservoir by using the traditional geological and logging methods. Based on the theory of seepage mechanics, we believe that the formation pressure difference and capillary pressure are the parameters controlling productivity. The fluid can be produced from the porous media only when the formation differential pressure overtakes the resistance of capillary pressure generated by reservoir fluids of different phases. Based on analysis of a large amount of mercury injection data, we built a model through multiple regression analysis for calculating average pore throat radius with porosity and permeability. The capillary pressure of each phase and equivalent differential pressures can be estimated according to the distribution patterns of each phase in porous media. Finally, a model was built to predict productivity and fluid properties with the "Differential Pressure Method". Five tested layers in 3 wells were chosen to verify the accuracy of this model. The results show that the evaluation results are basically consistent with the test results.
Huo Z.,China University of Petroleum - Beijing |
Pang X.,China University of Petroleum - Beijing |
Ouyang X.,SINO Geophysical Co. |
Zhang B.,Petrochina |
And 3 more authors.
Arabian Journal of Geosciences | Year: 2015
The upper limit of maturity for hydrocarbon generation (ULMHG) is represented by vitrinite reflectance (VR) that corresponds to the point at which the amount of further hydrocarbon generation is less than 1 % of the total hydrocarbon generation. Six methods were employed to study the ULMHG of the Cambrian and Ordovician carbonate source rocks in the Tarim Basin Platform (TBP), based on the mechanism of hydrocarbon generation, retention, and expulsion. These methods are reduction in atomic ratio for organic elements, variation in hydrocarbon generation potential, optimum simulation of organic materials based on material balance principle, thermal simulation experiment, variation in hydrocarbon retention amount, and variation in hydrocarbon expulsion amount. Studies showed that, although there are some differences between the results obtained using different methods, these differences are small. The ULMHG in the TBP varies from 4.10 to 4.84 % with an average value of 4.55 %, which is in good agreement with the characteristics of hydrocarbon generation under actual geological conditions. The VR of the Cambrian and Ordovician carbonate source rocks in the Tazhong uplift, the Bachu uplift, and the Tabei uplift ranges from 0.64 to 2.34 %, indicating that these areas have not reached the ULMHG. The VR in the Tadong area is very close to the ULMHG, and the VR of most source rocks in the Manjiaer sag has exceeded the ULMHG. In summary, the carbonate source rocks in the TBP have generated large amounts of hydrocarbons and still have high hydrocarbon generation potential to form large-scale oil and gas reservoirs, indicating good hydrocarbon exploration prospects in the deep parts of the TBP. Therefore, the study of ULMHG of carbonate source rocks is of great significance for evaluating the oil and gas resource potential and predicting favorable exploration areas in deep or carbonate rock formations. © 2014, Saudi Society for Geosciences.
Yang X.,Jidong Oilfield Company |
Zhang Z.,Sino Geophysical Co. |
Sun M.,Jidong Oilfield Company |
Shi W.,Jidong Oilfield Company |
Li R.,Sino Geophysical Co.
Oil and Gas Geology | Year: 2014
Temporal-spatial differences of syndepositional tectonics have profound impact on accommodation space, sedimentation rate, types and distributional characteristics of provenance systems of a basin. Episodic tectonic movement of the Nanpu Sag is a major contributor to accommodation space. Several NE-SW-trending contemporaneous faults that were developed in the period of Es in the southern provenance enhanced the compartmentalization of lake basin. A series of echelon growth faults extending toward the basin controlled the distribution of the Shahejie Formation. The linear subsags with the same strike as the growth faults formed in the downthrown blocks are the main unloading areas for sediments. The main depositional system is the combination of braided river delta, infralittoral subaqueous fans, beach bar and lake system in the southern provenance. On this basis, a model of contemporaneous fault controlling sandstone distribution is established in southern Nanpu Sag. The contemporaneous faults stretching into the lake basin controlled the sandstone distribution of braid river delta, with lobate deposits occurring laterally along strikes on the downthrown blocks of faults and superimposing vertically in the shape of wedges. The favorable objectives for future exploration are braided river delta, infralittoral subaqueous fans at the distal end of these deltas, and the beach bars developed on the tilted blocks.
Ma J.,China University of Petroleum - Beijing |
Chen X.,China University of Petroleum - Beijing |
Yao F.,China National Petroleum Corporation |
Zhang Z.,Sino Geophysical Co.
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting | Year: 2013
The discrimination and attenuation of internal multiples is very important in seismic multiple attenuation. The normal moveout difference between internal multiple and primary is small, so conventional methods based on moveout difference are almost invalid in the internal multiple attenuation. We discuss here predicted internal multiple subtraction based on wave equation methods. After some data pre-processing, we chose a layer, and predict all internal multiples related to the layer. The prediction process is a consistent convolution along the layer. The subtraction method that we used is the traditional least-squares adaptive subtraction method. Synthetic data examples illustrate the feasibility of the method.