| On the basis of the analysis of current exploration in Dinan uplift of Junggar Basin, this paper clearly indicates the major problem of lithologic reservoir exploration. Dinan uplift locates at a good structure location, using the rich three-dimensional seismic, geological and well log data, and based on improving the seismic resolution, this paper established the high-resolution sequence stratigraphic framework of Wutonggou group in Dinan uplift. Combined with various advanced geophysical methods, this paper implements the sedimentary facies distribution and sand prediction of Permian Wutonggou group, clears the sedimentary sequence controlling the gas reservoir, summarizes high-resolution sequence stratigraphy and lithology hydrocarbon models, and predicts favorable gas zone. The favorable drilling targets are optimized on the basis of the favorable gas sand tracking and accumulation comprehensive analysis.The main results are as follows:(1)Through the cores, well loggings, seismic, and analysis assay data, we establish the high-resolution sequence stratigraphic framework of Wutonggou group in Dinan uplift, and turn on the system tracts are divided and compared. We have studied the relation of sedimentary facies distribution within the sedimentary system, and revealed the main gas reservoir distribution. In this study area, SQ_P3wt1 high-stand systems tract is the main gas production segment. The main favorable hydrocarbon accumulation zones are mainly distributed in the distributary channel sand and distributary mouth bar of braided delta front at the tectonic uplift.(2)According to the known analysis of hydrocarbon accumulation factor, there are structural-lithologic reservoir and lithologic reservoir in the study area. The unconformity surface and fault is the dominative factor of hydrocarbon migration, and is the prerequisite of the reservoir formation. The sedimentary facies change is the second factor controlling the lithologic reservoir in Dinan region. There are two kinds of dominant migration pathway piont areas: the point area near cross section and the point area in the nose zone of the slope area.(3)Using the deconvolution method of post-stack mixed phase to develop effective wave frequency bands, the profile resolution is obviously improved, main frequency increasing about 7Hz ,and the bandwidth increasing 10-15Hz. The relations of wave group in profile resolution is well maintained, and the response of small thin layer amplitude is clearly shown. Those fully exploit the potential of seismic data, and satisfy the requirements of thin interbed lithologic reservoir prediction.(4)Using seismic data scan technology, 3D-visualization carving, sand body tracking technology of inversion data, extrapolation interpretation of favorable sand under the restriction of the phase model and other technology are used to analyze and predict reservoir in wutonggou group. According to the known gas reservoir to explain and predict favorable gas sandbody in Permian Wutonggou group, five sand, area 46.6 km~2. Among them, there are known three sand ,area 30.0km~2, predicted two, area 17.6km~2. Combined with the elements of controlling reservoir, hydrocarbon detection and oil-gas distribution, the five proposed well locations are disposed.(5)The high-resolution three-dimensional seismic data should be the primary condition in Lithologic reservoir exploration. On the basis of sand bed calibration in the three-order sequences system tract, we make full use of the advanced geophysical method for the analysis and prediction of sedimentary microfacies.we take full advantage of sandbody carving, strata slicing technology, seismic attributes, seismic inversion and hydrocarbon detection technology for the fine carving and prediction of favorable gas sand. Combined with comprehensive analysis of hydrocarbon accumulation, we optimize the favorable lithology body and drilling goal. |
PDF Full Text Request