Abstract:

Deep marine petroleum reservoirs draw great attention from the oil and gas industry around the world.Despite exploration breakthroughs made in deep and ultra-deep marine carbonate strata in Sichuan and Tarim Basins, Chinese oil companies are still facing many scientific and technologic challenges.This manuscript provides a review of research advances, technological bottlenecks and basic scientific problems relating to the deep marine petroleum accumulations and their exploitation in China; and, to meet the requirement of the national resource strategy, proposes to carry out studies based on analyses of the prototypes and transformation of the Upper Yangtze, Tarim and North China cratons.The studies include integrated multidisciplinary programs on petroleum accumulation and flow mechanisms in deep marine carbonate reservoirs and deep shale gas reservoirs, geophysical theories and methods for imaging and predicting complicated deep reservoirs, and new protocols and downhole tools for deep well drilling and completion.A strengthened analysis of the total factor and life cycle of basin formation, diagenesis, reservoir formation, hydrocarbon generation and accumulation, over a geological and human time scale, is also recommended to help establishing geological models of accumulation and transportation of conventional and unconventional oil and gas in deep marine strata for more reliable petroleum resource assessment and exploration prospect prediction.Future researches are suggested to be focused on solving key geophysical problems, including the low signal-to-noise ratio, low resolution, low imaging accuracy, and low amplitude-preservation, in the exploration of deep marine reservoirs.It calls for efforts made in the imaging and prediction of complicated deep structures and reservoirs, through enhanced technologies such as broad band seismic acquisition, complex structure modelling, anisotropic pre-stack depth migration(PSDM), and quantitative assessment of complicated reservoirs.Such engineering challenges in deep marine reservoirs as how to speed up drilling and maintain wellbore integrity are also suggested to be dealt with first as most of the reservoirs are featured in multiple production zones, strong heterogeneity, and high temperature and high pressure.

Key words: Safety drilling, complicated deep structure imaging, complicated deep reservoir prediction, deep shale gas, deep marine petroleum accumulation, marine carbonate, China