Study On Evaluation Method Of Logging Interpretation Of Triassic Compact Sandstone In

With the deepening of petroleum exploration and development, the economic value of tight sandstone gas reservoirs is gradually being recognized, and its exploration and development has become a hot topic and frontier issues of the domestic and foreign oil industry. The complex origin causes of formation and development of cracks, which not only makes the tight sandstone reservoir has the following characteristics:tight lithology, low porosity and permeability, strong heterogeneity and complex gas-water relationship, it also increases the difficulty of logging interpretation and evaluation of tight sandstone reservoir.This paper is viewing the Triassic tight sandstone reservoir at Luoyi region for the target. Because the area belong to the tight sandstone reservoir, combined with a low degree of exploration, has the following main problems during well logging evaluation:①No further study on characteristics of reservoir fractures, and crack evaluation is limited to qualitative description;②Difficult to predict the reservoir’s fluid properties;③Since there is no oil test data of the adjacent wells, and established quantitative standard of well logging interpretation, that is difficult to accurately evaluate the gas saturation of tight sandstone reservoir. Therefore, further study of tight sandstone reservoir well logging interpretation evaluation and establishes a set of suitable logging evaluation standard, which is play an important role in oilfield further exploration and developmentOn the basis of previous literature research, combining with the collection of conventional logging data and core physical properties, water analysis, imaging logging data, this paper process the logging evaluation at five aspects:reservoir characteristics, fracture identification and effectiveness evaluation, reservoir parameter modeling, fluid property prediction and logging data processing. Study showing:①Mineral composition between Tanzhuang and Chunshuyao formation is the same, and the main lithology includes lithic sandstone, lithic arkose and feldspathic lithic sandstone. The pore of Tanzhuang and Chunshuyao formation is0.6%-12%and0.4%-8.2%, and the permeation is (0.017-1.38) x10-3μm2and (0.015-19.1) x10-3μm2, both of them belong to low porosity, low permeability tight sandstone reservoir.②This area mainly developed large angle oblique cracks and high angle cracks, overall Tanzhuang formation fracture is more developed than Chunshuyao formation. Using Ik and imaging logging data to evaluation effectiveness of cracks. In addition, analyzed the influence factors such as rock particles, content of calcium, clay and dolomitic of fracture development.③Based on the core calibration of logging data, conventional reservoir parameter calculation models are established. Water saturation is calculated by Archie formula with a, b, m and n determined by experiment.④Among four fluid properties discriminant methods, fuzzy probability and Vp/Vs method has better effect than Resistivity-Acoustic and Resistivity-Neutron intersection method.⑤Using empirical statistical method and testing point constraint method to determine the lower limit of reservoir porosity and permeability. According to the Resistivity-porosity cross-plot of oil test reservoir determine the gas saturation limit of Tanzhuang and Chunshuyao formationThis paper would propose a feasible method of reservoir characteristics analysis, fracture identification and effectiveness evaluation, reservoir parameter modeling, fluid property discrimination and logging quantitative interpretation of Triassic tight sandstone reservoir in Luoyi district, and provide more dependable logging interpretation basis for the next step of exploration and development in this area.