According to the differences of structural deformation characteristics, the southern margin of the Junggar basin can be divided into two segments from east to west. Arcnate thrust-and-fold belts that protrude to the n...According to the differences of structural deformation characteristics, the southern margin of the Junggar basin can be divided into two segments from east to west. Arcnate thrust-and-fold belts that protrude to the north are developed in the eastern segment. There are three rows of en echelon thrust-and-fold belts in the western segment. Thrust and fold structures of basement-involved styles are developed in the first row, and decollement fold structures are formed from the second row to the third row. In order to study the factors controlling the deformation of structures, sand-box experiments have been devised to simulate the evolution of plane and profile deformation. The planar simulation results indicate that the orthogonal compression coming from Bogeda Mountain and the oblique compression with an angle of 75° between the stress and the boundary originating from North Tianshan were responsible for the deformation differences between the eastern part and the western part. The Miquan-Uriimqi fault in the basement is the pre-existing condition for generating fragments from east to west. The profile simulation results show that the main factors controlling the deformation in the eastern part are related to the decollement of Jurassic coal beds alone, while those controlling the deformation in the western segment are related to both the Jurassic coal beds and the Eogene clay beds. The total amount of shortening from the Yaomoshan anticline to the Gumudi anticline in the eastern part is -19.57 km as estimated from the simulation results, and the shortening rate is about 36.46%; that from the Qingshuihe anticline to the Anjihai anticline in the western part is -22.01 km as estimated by the simulation results, with a shortening rate of about 32.48%. These estimated values obtained from the model results are very close to the values calculated by means of the balanced cross section.展开更多
By using the integrated methods includingsandbodies modelling of the outcrops, sedimentary facies ofthe cores and well logs of the drilled wells, and the reservoircorrelation of interwells, it is thought that the sand...By using the integrated methods includingsandbodies modelling of the outcrops, sedimentary facies ofthe cores and well logs of the drilled wells, and the reservoircorrelation of interwells, it is thought that the sandstone res-ervoirs of Kela-2 gas field are a suit of high-quality naturalgas reservoirs with great thickness, extensive and continuousdistribution, high porosity and permeability, and a few bar-rier beds. Sedimentary facies and microfacies are the mainfactors controlling the reservoir distribution and interiorheterogeneity. Based on a great deal of data of rock’s thinsections, porosity, permeability, and the parameters of capil-lary pressure, the reservoir diagenesis, controls, mechanismand evolution of pores have been studied. It is consideredthat compaction in the early stage and diagenetic dolomiteand calcite cements have effect on the decline of reservoirsproperty. Now compaction is chiefly middle to weak. Thebetter reservoirs have no or a few calcite cements. In theearly of deep buried stage, there are still mainly remainderprimary intergranular pores. The authigenic kaolinite ofreservoirs is the production of the dissolution of feldsparsand lithic fragments. The dissolution results in the partlymodified and broadened secondary intergranular pores. Inthe late of deep buried stage, structure fissures and over-pressure were in favor of improving and preservation ofthese pores.展开更多
德惠断陷致密气藏储集层埋藏深、纵向跨度大、孔喉连通性差,高密度完井体积压裂技术虽实现了效益开发,但存在不同井间压后产能效果差异性大,稳产时间短的难题。通过对已施工井优质储集层厚度、铺砂强度、裂缝复杂程度和水锁伤害等因素...德惠断陷致密气藏储集层埋藏深、纵向跨度大、孔喉连通性差,高密度完井体积压裂技术虽实现了效益开发,但存在不同井间压后产能效果差异性大,稳产时间短的难题。通过对已施工井优质储集层厚度、铺砂强度、裂缝复杂程度和水锁伤害等因素与产能关系的分析,明确影响单井产能的主控因素,形成差异性射孔+“三段式”先成缝后成网+多级暂堵转向、防水锁压裂液体系等一系列压裂技术对策。经现场DS80-2井试验,压后第二天见气,见气返排率3.8%,日产气8.5×104 m 3,无阻流量19.2×104 m 3,为同区块同厚度气藏产量最高,见气返排率最低井;较设计产能提产20%,降本19%,达到提产控投的目的,为实现致密气藏高效勘探、效益开发提供了技术支撑。展开更多
基金financially supported by the National Natural Science Foundation of China(No.40972091)
文摘According to the differences of structural deformation characteristics, the southern margin of the Junggar basin can be divided into two segments from east to west. Arcnate thrust-and-fold belts that protrude to the north are developed in the eastern segment. There are three rows of en echelon thrust-and-fold belts in the western segment. Thrust and fold structures of basement-involved styles are developed in the first row, and decollement fold structures are formed from the second row to the third row. In order to study the factors controlling the deformation of structures, sand-box experiments have been devised to simulate the evolution of plane and profile deformation. The planar simulation results indicate that the orthogonal compression coming from Bogeda Mountain and the oblique compression with an angle of 75° between the stress and the boundary originating from North Tianshan were responsible for the deformation differences between the eastern part and the western part. The Miquan-Uriimqi fault in the basement is the pre-existing condition for generating fragments from east to west. The profile simulation results show that the main factors controlling the deformation in the eastern part are related to the decollement of Jurassic coal beds alone, while those controlling the deformation in the western segment are related to both the Jurassic coal beds and the Eogene clay beds. The total amount of shortening from the Yaomoshan anticline to the Gumudi anticline in the eastern part is -19.57 km as estimated from the simulation results, and the shortening rate is about 36.46%; that from the Qingshuihe anticline to the Anjihai anticline in the western part is -22.01 km as estimated by the simulation results, with a shortening rate of about 32.48%. These estimated values obtained from the model results are very close to the values calculated by means of the balanced cross section.
文摘By using the integrated methods includingsandbodies modelling of the outcrops, sedimentary facies ofthe cores and well logs of the drilled wells, and the reservoircorrelation of interwells, it is thought that the sandstone res-ervoirs of Kela-2 gas field are a suit of high-quality naturalgas reservoirs with great thickness, extensive and continuousdistribution, high porosity and permeability, and a few bar-rier beds. Sedimentary facies and microfacies are the mainfactors controlling the reservoir distribution and interiorheterogeneity. Based on a great deal of data of rock’s thinsections, porosity, permeability, and the parameters of capil-lary pressure, the reservoir diagenesis, controls, mechanismand evolution of pores have been studied. It is consideredthat compaction in the early stage and diagenetic dolomiteand calcite cements have effect on the decline of reservoirsproperty. Now compaction is chiefly middle to weak. Thebetter reservoirs have no or a few calcite cements. In theearly of deep buried stage, there are still mainly remainderprimary intergranular pores. The authigenic kaolinite ofreservoirs is the production of the dissolution of feldsparsand lithic fragments. The dissolution results in the partlymodified and broadened secondary intergranular pores. Inthe late of deep buried stage, structure fissures and over-pressure were in favor of improving and preservation ofthese pores.
文摘德惠断陷致密气藏储集层埋藏深、纵向跨度大、孔喉连通性差,高密度完井体积压裂技术虽实现了效益开发,但存在不同井间压后产能效果差异性大,稳产时间短的难题。通过对已施工井优质储集层厚度、铺砂强度、裂缝复杂程度和水锁伤害等因素与产能关系的分析,明确影响单井产能的主控因素,形成差异性射孔+“三段式”先成缝后成网+多级暂堵转向、防水锁压裂液体系等一系列压裂技术对策。经现场DS80-2井试验,压后第二天见气,见气返排率3.8%,日产气8.5×104 m 3,无阻流量19.2×104 m 3,为同区块同厚度气藏产量最高,见气返排率最低井;较设计产能提产20%,降本19%,达到提产控投的目的,为实现致密气藏高效勘探、效益开发提供了技术支撑。
