Hade 4 oilfield is located on the Hadexun tectonic belt north of the Manjiaer depression in the Tarim basin, whose main target layer is the Donghe sandstone reservoir, with a burial depth over 5,000m and an amplitude ...Hade 4 oilfield is located on the Hadexun tectonic belt north of the Manjiaer depression in the Tarim basin, whose main target layer is the Donghe sandstone reservoir, with a burial depth over 5,000m and an amplitude below 34m, at the bottom of the Carboniferous. The Donghe sandstone reservoir consists of littoral facies deposited quartz sandstones of the transgressive system tract, overlapping northward and pinching out. Exploration and development confirms that water-oil contact tilts from the southeast to the northwest with a drop height of nearly 80m. The reservoir, under the control of both the stratigraphic overlap pinch-out and tectonism, is a typical subtle reservoir. The Donghe sandstone reservoir in Hade 4 oilfield also has the feature of a large oil-bearing area (over 130 km2 proved), a small thickness (average efficient thickness below 6m) and a low abundance (below 50 × 104t/km2). Moreover, above the target layer developed a set of igneous rocks with an uneven thickness in the Permian formation, thus causing a great difficulty in research of the velocity field. Considering these features, an combination mode of exploration and development is adopted, namely by way of whole deployment, step-by-step enforcement and rolling development with key problems to be tackled, in order to further deepen the understanding and enlarge the fruits of exploration and development. The paper technically focuses its study on the following four aspects concerning problem tackling. First, to strengthen the collecting, processing and explanation of seismic data, improve the resolution, accurately recognize the pinch-out line of the Donghe sandstone reservoir by combining the drilling materials in order to make sure its distribution law; second, to strengthen the research on velocity field, improve the accuracy of variable speed mapping, make corrections by the data from newly- drilled key wells and, as a result, the precision of tectonic description is greatly improved; third, to strengthen the research on sequence stratigraphy and make sure the distribution law of the Donghe sandstone; and fourth, with a step- by-step extrapolation method, to deepen the cognition of the leaning water-oil contact, and by combining the tectonic description and drilling results, to make sure little by little the law of change of the water-oil contact. The exploration and development of the Donghe sandstone subtle reservoir in Hade 4 oilfield is a gradually perfected process. From 1998 when it was discovered till now, the reservoir has managed to make a benign circle of exploration and development, in which its reserve has gradually been enlarged, its production scale increased, and, in a word, it has used techniques necessary for this subtle reservoir in the Tarim basin.展开更多
The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a numb...The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.展开更多
文摘Hade 4 oilfield is located on the Hadexun tectonic belt north of the Manjiaer depression in the Tarim basin, whose main target layer is the Donghe sandstone reservoir, with a burial depth over 5,000m and an amplitude below 34m, at the bottom of the Carboniferous. The Donghe sandstone reservoir consists of littoral facies deposited quartz sandstones of the transgressive system tract, overlapping northward and pinching out. Exploration and development confirms that water-oil contact tilts from the southeast to the northwest with a drop height of nearly 80m. The reservoir, under the control of both the stratigraphic overlap pinch-out and tectonism, is a typical subtle reservoir. The Donghe sandstone reservoir in Hade 4 oilfield also has the feature of a large oil-bearing area (over 130 km2 proved), a small thickness (average efficient thickness below 6m) and a low abundance (below 50 × 104t/km2). Moreover, above the target layer developed a set of igneous rocks with an uneven thickness in the Permian formation, thus causing a great difficulty in research of the velocity field. Considering these features, an combination mode of exploration and development is adopted, namely by way of whole deployment, step-by-step enforcement and rolling development with key problems to be tackled, in order to further deepen the understanding and enlarge the fruits of exploration and development. The paper technically focuses its study on the following four aspects concerning problem tackling. First, to strengthen the collecting, processing and explanation of seismic data, improve the resolution, accurately recognize the pinch-out line of the Donghe sandstone reservoir by combining the drilling materials in order to make sure its distribution law; second, to strengthen the research on velocity field, improve the accuracy of variable speed mapping, make corrections by the data from newly- drilled key wells and, as a result, the precision of tectonic description is greatly improved; third, to strengthen the research on sequence stratigraphy and make sure the distribution law of the Donghe sandstone; and fourth, with a step- by-step extrapolation method, to deepen the cognition of the leaning water-oil contact, and by combining the tectonic description and drilling results, to make sure little by little the law of change of the water-oil contact. The exploration and development of the Donghe sandstone subtle reservoir in Hade 4 oilfield is a gradually perfected process. From 1998 when it was discovered till now, the reservoir has managed to make a benign circle of exploration and development, in which its reserve has gradually been enlarged, its production scale increased, and, in a word, it has used techniques necessary for this subtle reservoir in the Tarim basin.
基金The work was supported by the National Science and Technology Major Project of China(No.2016ZX05003-004).
文摘The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.
