Gas-water Identification Technology And Its Application In SLG Region

SLG region is the main gas field of Chinese inland,which is a typical trapping gas reservoir.The characteristics of its main reservoir H8 is low porosity,low permeability,low abundance.And Its gas reservoir is small scale at local.The main production layer H8 has the weak ductility of sand body and the weak connectivity of effective sand body. The reservoir is strong heterogeneity and has no uniform gas-water interface of layer H8, which has a quite complicated relationship between gas and water.Aiming at the condition of the complex gas-water relationship in SLG region,this article firstly analyze many kinds of the current commonly used theories of gas-water identification methods, and then combine with logging, seismic and geological data in the SLG region, finally put forward a set of gas-water identification technology series which is suitable for the study area.This thesis mainly gets three key research results as following:(1) A set of gas-water identification technology series has been developed suitably for SLG region,which improved the conventional methods from six aspects:?using the characteristic noise elimination method of layer flattening plus edge-preserving smoothing to improve the signal to noise ratio and resolution,to keep the edge information better,to lay the foundation of later inversion;?using Shear wave velocity prediction method with high precision to make up for the deficiency that only 2 wells had shear wave data in the work area;?using the extended elastic impedance inversion suitably for area of strong heterogeneity to inverse pre-stack elastic parameter;?optimizing gas-water identification factors on the basis of the work area pre-stack elastic parameters;?using post-stack stochastic inversion to fit log parameters;?Jointing pre-stack and post-stack parameters to identify the gas and water in order to reduce the influence of the uncertainty of parameters and improving the gas-water identification accuracy.(2) Gas-water distribution characteristics of the SLG region has been analyzed with the gas-water identification technology developed in this paper.That is the gas is generally but strong dispersion, The local gas enrichment regions are less, the gas-water production areas are more.(3) The location of a well with high development potential has been suggested.This well is located in the structural high position. The development of its reservoir and sand body is good. And it has the characteristics of gas enrichment. So this well has the very high value of exploration and development.Real data results show that the application effect of the proposed gas-water identification technology series in SLG region is good.And it provides a good technical support for this region of gas-water identification, has important theoretical and practical application and popularization value.