Quantitative Research Of The Conducting Performance Of Dense Sandstone Transportation Systems

In this thesis, by the use of drilling core, formation test, well logging, laboratory analysis and other kinds of data, based on the analysis of regional geological background, we analyzed the oil migration system in the dense sandstone reservoir, of the HH oilfield in the Ordos basin. The study shows that there are two types of oil migration system developed in the research area, including the sand body as a migration system and the fractures as a migration system. The sand body of underwater distributary channel is the most developed sand body type in the research area. Through the distribution of sand body connectivity, planar distribution, profile of research, shows that Chang 812 has the highest development, large thickness and wide distribution. It has developed three sets of single sand layer, along with northeast to southwest and high degree of sand bodies superimposed. The sand body development of Chang811 and Chang 813 is low and ranges small. The factors that may influence sand migration capacity of the sand body is diagenes, physical poroperties of sandstone and so on. The porocity and permeability in sand stone become lower because of compaction and cementation. The solution, replacement, alteration may improve the migrate ability of sand stone. Take use of porocity and permeability and other parameters to quantitatively performance the oil migration system, the average porocity is 8.9%, and average permeability is 0.31×10-3μm2 in Chang811, Chang812 is the main layer of oil, and the porocity is 6%~14%, part of them are greater than 16%. the permeability is 0.2~0.5×10-3μm2, some zones in middle section may higher than 0.5×10-3μm2, and the best physical properties accur in the wellblock of HH37 and HH1052, the second is in the wellblock of HH41 and HH19.Based on the field investigation of cracks and the description of core fractures, taking use of the data of imaging log and well log to identify the effective natural cracks, summarizing the characteristics of the cracks. The mainly cracks in the area are high-angle and vertical cracks, dominantly in the NE-SW group, secondly in the NW-SE group. The cracks cut through the different lithological layers vertically, extend can reach several meters. Use the parameter of opening and porocity to quantitatively performance the oil migration system, and forecoas the section of fracture development, the fracture is mainly developed in the wellblock of HH70、HH48、HH19、HH125、HH30、HH1052、HH41、HH16、ZJ29.Comprehensive consideration of the effective thickness, porocity, permeability and the distribution of fracture, from the macro and micro to analysis the effectiveness of the oil migration system, quantitatively performance the oil migration system, based on the hydrocarbon accumulation model, forecast the favorable regional gathering of HH oilfield.