Volcanic Reservoir Parameter Evaluation Of Well Logging For Yingcheng Formation In Changling Depression, South Songliao Basin

Volcanic reservoirs are widely distributed in many basins in the world, which is rich in oil and gas resources. In recent years, with the increased demand for oil and gas resources and exploration to increase difficulty, actively exploring new areas of volcanic gas exploration to find new reserves replacement has become an important of exploration.The complexity of rock composition and structure and the multiplicity of the pore space and the uneven random distribution of Songnan Gas Reservoir results the reservoir stratum highly heterogeneous. Accordingly it was difficulty to effectively divide the reservoir, reservoir parameters and correctly identify the nature of pore fluid. In order to solve the difficulty problem in deep gas exploration of Songnan gas reservoir evaluation, it is necessary to form a more complete and efficient reservoir evaluation logging.The main objective of this thesis is to complete the theoretical evaluation of geophysical logging and interpretation technique.The main research contents include:1. It conducted the data and analyzed the region's geology, core and logging data.2. It analyzed the logging features and relationships of Four Characters, which includes lithology and reservoir characteristics (porosity, permeability), oiliness and physical properties and determined the top and the bottom reservoir interface and a variety of rock frame parameters of each well for the subsequent calculation of reservoir parameters.3. This thesis calculated porosity the porosity, including matrix porosity, fracture porosity an total porosity calculations. Among them, the matrix porosity is acquired from the core data regression, rate formula and directly calculating the Willie formulas, the fracture porosity calculated using the resistivity method of LLD and LLS logging and simplified equation considering the occurrence of fractures, the total porosity calculated using neutron or density logging data, but for wells containing borehole enlargement only neutron calculations.4. In reservoir permeability calculation, the permeability was calculated mainly using core permeability with logging data of the corresponding regression formula.5. Reservoir water saturation was calculated using respectively Archie formula, saturation model based on conductive path, two-pore system model and three-pore system model. For Lining formula, it is more suitable for calculation of the reservoir saturation of non-homogeneous but it is difficulty to strike each parameters of the formula because data limitations the paper did not use the method.6.Reservoir fluid identification adopted the technology of plate, neutron and density porosity cross plots, using dipole array acoustic logging data DSI wave slowness ratio, volume compression coefficient method, Poisson Ratio method and P-wave modulus difference ratio method for identification of gas and water layer.7.Form the calculation of reservoir parameters and fluid identification of a comprehensive explanation it was divided into several gas-bearing section and the water layers.The research in the use of conventional logging data calculation of reservoir parameters and fluid identification, try a number of ways, from the application and the analysis, obtained for the following understanding:1. Calculated on the Archie water saturation: the result calculated from the formula of the Archie is water saturation of rock matrix. In practice, it is need to accurately determine the m, n and other petro-physical parameters, and requires a lot of core rock electronic experimental data, and need to carry sophisticated equipment, it need the higher the cost.2.Conductive path-based model of water saturation:This method is more sensitive to low resistivity values,and the values of water saturation obtained may be too large.3.Li Ning model on water saturation: Li Ning model taking into account the anisotropy of rocks, deduced through mathematical precision, and has a strong general, but in practice, if you want to get higher accuracy, requires too many parameters, to data limitations.4.On the dual porosity model and the triple pore water saturation model: dual porosity model and the triple-porosity models are identical in nature, in which the double porosity model is a special case of the triple porosity model. Both of which are for the complex with cracks and holes calculated porosity reservoir. The essence of both is derived exactly as cracks and holes of the system to change the cementation index m. Accordingly it corrected the saturation caused by the change due to the heterogeneity of the reservoir water. Therefore, in order to accurately obtain the m value, it requires accurately determine the matrix porosity, fracture porosity and total porosity, etc. Using conventional logging data with NMR data, micro-resistivity tomography scans and other imaging logging data will facilitate the determination of various porosities.5.On the detection of gas formation: gas and water layer identification plate method, while more concise application of intuitive, but the application effects is restricted by the oil test results and the number of testing points and data points whether or not representative. Using dipole shear wave logging data, the instructions on the gas is strong, but not all wells have the data, data access to this method brings certain limitations. Some indicators of law, such as the method of calculation of volume compression coefficient matrix need to use density values, so the density of the strike will also affect the skeleton to the method and its application. If you have a dipole shear wave logging data, reservoir lithology, physical properties, as well as cracks in the rock withstanding stress and other factors also affect the effective recognition of the effect of fluid. In order to effectively identify gas and water layer, various methods should be combined effectively integrated application.