Study On Prediction Technique With Reservoir Baxian Sag Niudong Buried-Hills Belt

Buried hills drilling of Baxian Sag began in1977, and11buried hill reservoirs were found. Proven reserve of buried hills accounting for53.7%oil and100%natural gas of all the reserve in Baxian sag, it has made a significant contribution to the development of the national economy. With the improvement of their exploration level, middle and shallow larger buried hills have been basically drilled. However, deep buried hills, buried depth below than5000m, were in a lower exploration level. Over the past decade, although drillings of deep buried hills have been carried out, all failed because of relatively outdated technology. Confirmed by drilling, deep layers of Baxian Sag, member4of Shahejie formation and Kongdian formation have good oil generation and source conditions. And they still have a higher potential exploration value. In2011, the design drilling of Niudongl well in buried hill belt achieved a great breakthrough, which proved the rich accumulation conditions of deep buried hills.Because of deep bury of buried hill in Niudong buried hill structure belt, weak energy of deep seismic data, low signal noise ratio, they brought greater difficulty to the identification of buried hills and accurate implementation of traps. Besides, from the slope to Baxian sag direction, the uneven thickness and wedge distribution of Carboniferous, Permian, and Cambrian strata had a greater impact on the underlying reservoir capacity of Wumishan reservoir. But it’s difficult to accurately identify the distribution range of Carboniferous, Permian and Cambrian strata with present seismic data. It’s also tough to predict buried hill reservoir distribution and hydrocarbon from qualitative to quantitative. And therefore, a reliable basis to drilling and reserve calculation cannot be provided. By fine handling of reverse-time migration, buried hill reservoir prediction, time-frequency electromagnetic and other geophysical techniques and methods et al, trap morphology of deep buried hills, reservoir distribution and hydrocarbon prediction were implemented. And a favorable target was carried out for risk exploration, which was expected to be a major breakthrough.