Progress of exploration operation technologies for shallow lithologic reservoirs in Bohai Sea
In recent years,Neogene shallow lithologic reservoirs have gradually become an important field in the exploration and discovery of reserves in the Bohai Sea.The shallow lithologic reservoirs are dominated by fluvial facies deposits and shallow water delta deposits,with wide horizontal distribution of reservoirs,vertical interbedding of thin sand and thick mud,loose lithology,and viscous oil,resulting in high exploration cost,difficulty in capturing drilling cores,and challenges in obtaining crude oil samples and achieving commercial productivity.During the"13th Five-Year Plan"and"14th Five-Year Plan"periods,the technical system of shallow exploration operation in Bohai oilfield has been gradually established through the combination of production,learning,research,and application in terms of shallow exploration drilling efficiency improvement,shallow exploration data acquisition(drilling coring of loose sandstone and heavy oil cable sampling of loose sandstone),shallow exploration productivity release(geochemical crude oil density prediction and heavy oil cold production test of loose sandstone),and shallow exploration interpretation and evaluation(low-contrast oil formation identification).From 2019 to 2023,the low-cost and high-efficiency evaluation of four large and medium-sized shallow lithologic heavy oilfields has laid a solid technical foundation for the continuous in-depth shallow lithology exploration in the Bohai Sea and has important reference significance for promoting the shallow lithology exploration and development of offshore oilfields in China.
Bohai SeaNeogeneshallow formationlithologic reservoirexplorationdrilling efficiency improvementdata acquisitionproductivity releaseinterpretation and evaluation