Reservoir Evaluation And Geology Parameter Optimization Of Horizontal Well In Offshore Zone

Offshore zone is the hot field of oil exploration and production in China currently. Because of the speciality of its geography location, both oil exploration and production are different in comparison with continental oilfield. They are characteristics of high investment, high risk, high science and technology. So, before oilfield development, the precise, fine reservoir evaluation is of importance to decrease development risk and increase development benefit. Due to little exploration well and evaluation well, large well-spacing, dominated by seismic data, the limitation of direct geology information for recognizing reservoir, many problems and difficulties in recognizing reservoir, building geology model will be meet and should adopt some special technologies and measures. In addition, the large rake well and the horizontal well is often applied to the development of offshore oilfield. The geology parameter optimization of the horizontal well is the key to the successful development of reservoir.According to the characteristics and request of reservoir evaluation in offshore zone, combining the Zhangdong development zone of Chenghai oilfield in Dagang, this paper formed a series of reservoir evaluation technologies and methods for this kind of zone. The integrated reservoir evaluation method adapted to the period of reservoir evaluation in offshore zone which is restricted by sequence stratigraphy framework, guided by geology concept model and driven by seismic data was put forward. A breakthrough cognition of the reservoir geology character in Zhangdong development zone of Chenghai oilfield in Dagang is attained through the all-round, serially application of all kinds of modern reservoir description technologies. The viewpoint of the oil and gas distribution heterogeneity caused by lithology, diagenetic facies and the complexity of fault and fracture system on the background of tectonic reservoir was put forward. And scientific evaluated the heterogeneity reservoir. A fine, precise 3D quantitative reservoir geology model was build applying the integrated technologies including 3D seismic structure interpretation, stochastic simulation seismic inversion, geology modeling, numerical simulation. The result of 3D seismic structure interpretation and seismic inversion data cube were taken as the input of the frame model and property model. This could exert the transverse resolution advantage of seismic data to resolve the problem of large well-spacing, the difficulty in inter-well reservoir prediction. The method workflow of choosing the fault block adapted to development using the horizontal well and the geology parameter optimization of the horizontal well was given. Based on the reservoir evaluation in Zhangdong development zone, the fault block Zhanghai5 was chose to analyze the horizontal well geology parameter optimization. The production effect is best if the horizontal segment length is 600m, the direction is Northeast and the distance to the top is two fifths.The checkout by reservoir numerical simulation and analysis of production application effect show, the geology cognition and the geology model of this zone is credible. This provides the important technology support for the following developmet scheme design of Zhangdong development zone. It also provides the reference for the analogical zone.