Discovery of large deep-water and deep-formation oilfield in south Kaiping sag of Pearl River Mouth basin and new geological understandings
Kaiping sag is one of the most geologically complex sags in Pearl River Mouth basin,and it is also an important area of deep-water oil and gas exploration potential.Due to the unclear understanding of sag structure,hydrocarbon source distribution and hydrocarbon accumulation law,the exploration process has been restricted for a long time.Based on the detailed interpretation of three-dimensional seismic data,a comprehensive study of basin-forming mechanism,development of hydrocarbon source rocks,source-sink system and main controlling factors of hydrocarbon accumulation was carried out.Recently,a large-scale medium-light oilfield exploration discovery was obtained in south Kaiping sag.To further guide exploration,oil and gas accumulation conditions in Kaiping sag were analyzed,and oil and gas accumulation models were summarized.The results indicate that:① Kaiping sag is a"detachment-nuclear complex"type sag developed under the background of strong extensional continental margin in the northern South China Sea,and has experienced three rifting periods of"rifting,detachment rifting,and fault-depression transformation".②High-quality lacustrine source rocks of Wenchang Formation are developed in Kaiping sag,with a wide distribution range and great hydrocarbon generation potential.Source rocks are generally in a mature to high mature stage.③The oil and gas migration in Kaiping sag is controlled by the coupling of"ource-fault-ridge".Three nose-shaped uplifts in south Kaiping sag are favorable areas for oil and gas accumulation,with an overall pattern of strong charging near the source,differential migration and accumulation controlled by fault-ridge,and rapid accumulation in the late stage.Discovery of the large-scale light oilfield in the Paleogene system of south Kaiping sag has achieved a significant breakthrough in the exploration of Kaiping sag.It has not only opened up a new area and a new field of deep-water oil and gas exploration in Pearl River Mouth basin,but also provided a reference for the exploration of"detachment-nuclear complex"type oil and gas bearing basins.
Pearl River Mouth basinKaiping sagdeep-waterdeep-formationPaleogenesouth Kaiping sagKP 11-4KP 18-1
万方数据
维普
