Application of Seismic Prediction Technique on Complex Lithological Reservoir in SL Oilfeild

In recent years, the proven reserves of lithological reservoirs account for a little more than two-thirds of the total proven reserves in SL Oilfield. The seismic predication technique as the key exploration method of lithological reservoirs focuses on identifying and describing reservoirs, especially on sand bodies. For the lacustrine faulted basin with various complex lithological reservoirs, based on the different geological characteristics of the reservoirs, a series of techniques suitable for channel sand, sandy conglomerate, turbidite and beach bar reservoirs have been developed and applied in the lithological reservoir identification and description and have made great progress in the actual exploration.PrefaceSince 1990s, the exploration in SL Oilfield has already developed to that of subtle reservoirs. The proven reserves of lithological reservoirs account for nearly 70% of the total reserves. The seismic predication technique as the key exploration method of lithological reservoirs focuses on identifying and describing reservoirs, especially on sand bodies. For lithological reservoir exploration in complex geologic conditions, lots of studies have been completed in order to obtain great success in many areas [1-7]. With the increasing degree of exploration, lithological reservoirs will become the key role in the future. It is very important to apply geophysical data for identification and description of lithological reservoirs. It has significant effect to improve exploration benefit and the production.

Wuerxun Depression Fan Delta Depositional System Research of Nantun Formation in Wubei Sub-Depression

Fan delta facies deposition are developed in the steep slope of faulted lake basin and have features ,such as the rapid accumulation, from near provenance, clastic coarse granularity and poor sorting. By means of core, logging, well logging and seismic data, based on the sedimentary characteristics of Nantun formation of Wuerxun depression, the conclusions are as followings: Faulted basin steep slope belts are developed fan delta depositional system with volcano facies in Wubei sub-depression of Wuerxun depression;The fan delta system are divided into plain,front and front fan delta etc,three subfacies, seven microfacies; In distributary channel microfacies, sand conglomerate, gravel sandstone, middle-grit are main lithology, low maturity, poor sorting to medium, vertical sequence, visible bottom gravel and erosion surface, large scale cross-bedding are developed, partial visible horizontal bedding; channel mouth bar microfacies relatively rudimentary, lithology with sorting relatively good powdermiddle sandstone, development of small cross-bedding, horizontal bedding.

Fluid Flow of Daxing Conglomerate in Langgu Depression and its Controlling Effects on Reservoir

The Daxing conglomerate in Langgu depression is typical glutenite fan sediment in steep slope belt of faulted basin. By analyzing the data of core, petrographic thin section, scanning electron microscope and “X” ray diffraction, we’ve found that fluid flow controls the reservoir development to a certain degree. The results show that there are four types of fluid affecting the reservoir of Daxing conglomerate-meteoric fresh water, organic acid, alkaline fluid and abnormal high pressure fluid. We’ve studied fluid flows in different diagenetic stages combining the observation of clay mineral and carbonate cement and we find that two acid fluid events and abnormal high pressure fluid have determined the development of three pore belts in the longitudinal section.

Mechanism Analysis of Tectonic-Type Ground Fissures in Shanxi down-Faulted Basin

Shanxi downed-faulted basin mainly consists of Datong basin, Taiyuan basin, Linfen basin and Yuncheng basin, having thick quaternary stratum. Affected by geological structure, topography, stratum conditions and other factors, ground fissure disasters are well developed. Using the development and evolution of tectonic-type ground fissures in the faulted basin as research objects, from the two aspects of horst-graben structure and basal activity of fault belt, this study explored the causes of quaternary ground fissures in Shanxi down-faulted basin. Studying the distribution characteristics, formation mechanism and the disaster-causing effects has the theoretical significance of a better summary and understanding on ground fissures and other geological disasters, as well as providing theoretical basis for prediction and prevention means of the disasters.