Distribution Rule Of Gas And Water In Taiyuan And Shanxi Formation In North Of The East2Area Of Su Li Ge Gas Field

Whether the reservoir lithology, pore structure or gas-water distribution in the North of the east2area of Sulige Gas field is very complicated. The gas reservoir in Taiyuan and Shanxi formation of this area is characterized by tight sandstone with low porosity and poor permeability, as well as small pore-throats radius, poor physical properties and high heterogeneity. The early exploration and development shows the difficulty to identify gas and water layer. The sand distribution rule, the cause of water-producing gas well, connectivity of formation water, distribution rule and controlling factors of formation water in this research area are still at the first stage. In order to improve the success and efficiency of construction and production, and to develop the gas well reasonably, this paper studies on hydrochemical features of formation water, identification of gas and water layer, physical property and distribution of sandstone, distribution rule and controlling factors of formation water based on the studies of former researchers on this area combining core, log interpretation, thin sections and data of water quality analysis of the research area, achieve the following results and cognitions:1. According to log interpretation, hydrochemical analysis and well testing data, the type of produced water is classified into three kinds:normal formation water, ontzilte formation water and raffinate. Analysied by hydrochemical property index it is considered that the fluid system of the formation has good sealing property in this region.2. The identification of microslides, shows the reservoir characteristics of Taiyuan and Shanxi formation such as lithology and physical property, identification standards of electrical property of sand-mud stone was made combining well log and core observation. The distribution rule of the sand bodies were further studied: Sandbody of Shanxi formation in this region is mainly along north-south direction, often distributing in the shape of straps. Sandbody overall in parallel source direction is outspread, continuity, and vice-versa for vertical direction.3. Combining the data of well test, hydrochemical analysis as well as the log curves, this paper distinguished fluid in the reservior of single well, and then get the best fluid identification technique of this area through comparison, the Porosity-Resistivity cross plot technique is strongly recommended, assisting with gas volume mothod and multiple discriminant analysis as well.4. Discrimination of low resistance gas reservoir for part of the identification process of the air-water layer is not applicable to the above method; the causes of low resistivity gas are discussed, Analysts believe that the main reasons for the area caused by low resistivity gas:are high immobile water saturation、the low amplitude structure、clay conductivity additional complcated pore structure.5. Both the Taiyuan and Shanxi formation produce gas and water. Combining the fluid recognition, the horizontal and vertical distribution of water is predicted. The general type of formation water is divided into three types, local river basal and edge water, lens body water and compact layer residual water. On the point of strata, the water amount and number develop best at Shan23section, while considering place, Su77well block is more enriched than Zhao51well block of formation water. Combining geological and other factors, the basis of the fluid allocation is basically determined by sandstone distribution, and also by sandstone microstructure and reservoir heterogeneity.