关键词: 河套盆地, 临河坳陷, 白垩系-古近系, 吉兰泰潜山, 重要发现

Abstract: The Linhe depression of Hetao Basin is a Meso-Cenozoic strike-slip pull basin. The early stage wells were mainly concentrated in the slope zone, which had oil and gas shows but no substantial breakthroughs. Recently, new and old data including gravity, magnetic, electric, seismic, drilling and geology data were used to investigate the basin property, structural characteristics, resource potential and reservoir-cap combination. It is understood that the depression is a strike-slip pull depression, which is zoning east-west and blocking north-south. Two major source rocks in the Lower Cretaceous and Oligocene respectively are confirmed. Three sets of source-reservoir-cap are identified. Indepth comprehensive analyses of the trap-source relationship and the oil and gas accumulation models showed that the Jilantai buried hill is favorable for oil and gas accumulation for its adjacency to the northern deep sag hydrocarbon generation area with Langshan piedmont fault as the main channel for oil and gas migration providing good lateral oil supply conditions. The Jilantai buried hill and its periclinal fault structural belt were selected to deploy Well JHZK2, Well JHZK7 and Well Jihua 2x. All of the three wells have obtained industrial oil flow, which was a great discovery of Linhe depression and demonstrated a broad exploration prospects. With the attention of PetroChina Company and the support of Changqing Oilfield Company as the basis, the innovative geological understanding and scientific deployment and decision-making as prerequisites, the thought-transform and key point-selecting as the key and the selection of economically applicable technologies as the guarantee, the Linhe Depression successfully achieved rapid exploration.

Key words: Hetao Basin, Linhe depression, Cretaceous-Paleogene, Jilantai buried hill, significant discovery