Research On Seismic Inversion In The Second Member Of Shahejie Formation-Dongying Formation Of Wen’an Slope,Baxian Depression

Wen’an slope is located in the east of Baxian sag in Jizhong depression, which is bounded to the east by Dacheng salient; to the west by Baxian sag and Maxi-Mozhou sag. It extends to the south of Nanmazhuang tectonic belt in Raoyang sag, and is separated to the north from Wuqing sag by Litan fault. In recent years, Wen’an slope zone has been the main study area in the oil-gas exploration and development. The main reservoir type is dominated by the lithology and lithology-structural reservoir. In order to solve the reservoir prediction problems raised from the special structure of the study area and deposition., we carried out constrained sparse spike inversion techniques, high resolution seismic prediction techniques, and the processing and interpretation of the wave impedance body.Seismic inversion is composed of prestack inversion and post-stack inversion. Currently, the most widely used inversion is post-stack inversion. Post-stack inversion include CDP integral, recursive inversion, model inversion and geostatistical inversion. This paper explains application of vertical high-resolution logging data and horizontal continuity of the seismic data, which include abundant lithological and physical properties information. The conversion of interface of the seismic data to the rock of the logging data is established in order to compare with drilling and logging data directly, and process geological interpretation of rock units. The study of spatial variation in reservoir characteristics and distribution characteristics description of reservoir can be used as important basis for the oil-gas exploration and development.Constraint sparse-spike inversion method is a recursive inversion method based on the sparse pulse deconvolution. The basic hypothesis is that the formation of reflection coefficient is sparse. By using the trend and scope of seismic interpretation layer and well-controlled wave impedance, a fast, trend-restricted pulse algorithm is applied to generate a wideband results. The inversion results are consistent with the seismic data. Also, these results supplement low and high frequency components at the same time, thus vertical resolution is significantly improved compared with the conventional seismic data.Geostatistics inversion technology, using the characteristics of correlation exists between seismic wave impedance and reservoir attribute, combined with seismic stochastic inversion and geological statistical simulation technology, the seismic, geological and logging data can be made the best use of to create a consistency between the reservoir property description results and geological statistics and seismic inversion double anastomosis. This result nicely reflects heterogeneity and uncertainty of the spatial reservoir attribute distribution. Geological statistical inversion method takes the structure and randomness of the reservoir parameters in space into consideration, so the inversion results are more conformable to geological conditions. Geostatistical inversion requires a certain number of wells to have preferable geological statistical properties. Therefore, geological statistical inversion is mainly applied to the middle stage and late stage of oil field development.. At the same time, the geological statistics inversion can produce multiple equal probability results, and therefore a detail study on all the results is required to select the most suitable result which is consistent with actual geological conditions.According to the feasibility analysis of seismic inversion of the study area (including geological characteristics of the study area, seismic data quality, pre-logging data, and the reservoir impedance characteristics and so on), a "two-step" inversion method is formulated. Firstly, constrained sparse spike inversion is processed to understand the scale of the reservoir, distribution characteristics and so on, then high-resolution geostatistical inversion is completed.For the lithologic interpretation of impedance data of the inversion, considering the affect of compaction and special lithology(volcanic rock, carbonate rock), classical unitary threshold method is invalid for reservoir interpretation. In this paper, we use the lithologic plate to interpret the impedance data, and then get sandstone percentage data and lithology data. This interpretation method considers the compaction for the impedance of reservoir, therefore, the affect caused by volcanic rock and carbonate rock can be removed, and the uncertainty in interpretation of inversion results is well resolved.Seismic inversion technique is widely used in reservoir prediction. This paper mainly introduces its application in determining reservoir boundaryand application in3D geological modeling and sedimentary facies prediction. In addition, seismic inversion can provide suggestions on well deployment.