| Sinopec Daylight,which is operated by Sinopec in Canada, has the biggest tight sand oil and gas reservoir of Sinopec overseas.The permeability and porosity of this tight oil and gas sand martrix are very low, so facing problems like low production of single well,difficult to supply zone energy,and poor economic profit. Precently, the main method to increase tight sand oil and gas production is horizontal fracturing.However, the fracturing stimulation mechanism seems to be not suitable for openohle fracturing technology in Sinope Daylight.New methods and technologys are in need to increase tight sand oil and gas production and economic profit of Sinopec Daylight. Based on these issues, main research works are as follows:Daylight tight sand oil and gas reservoir characteristics and development difficulties were studied.Fracture flow conductivity, double linear seepage and complex fracture networks were summarized as three key factors for horizontal well fracturing stimulation.With Near well bore Model numerical simulation, the impacts of frature parameters on production were studied.The dynamic stress balance between fracturing fluid and well bore was considered in openhole horizontal well without perforation, and the crack initiation formula was established for the openhole horizontal well in permeable reservoir.With combination of this formula and the instance fraturing data under supervision of microseismic, fracturing mechanism was analyzed. Based on the analysis of water blocking problems when a lot of fracturing fluid was remained after fracturing operation in gas reservoir, the application mechmanism of gas wetting alteration method and numerical simulation were studied,and the result showed that this method was suit to increase flowback efficiency and gas well production.On the base of study on well completion types, fracturing fluids, proppants and factory fracturing technology, horizontal well fracturing instances in Sinopec Daylight tight sand oil and gas reservoir were studied, and the result showed that compared with plug and perf technology, one stgage cost of openhole packer sliding sleeve fracturing technology saved 30%-50% costs.And with the same probability and sand quantity, daily production increased significantly, and with the increase of proppant quantity, more probility to have highly production wells.The slick water fracturing fluid saved 50% costs and had 3 times daily production more than oil based fracturing fluid. And the daily production increased by 25%-100% more than nitrogen foam fracturing fluid. Simultaneous fracturing technology could be used to decrease costs and increase production and efficient.Therefore, a proper stimulation program was selected and implemented in Daylight field. And the result showed that operation time and fracturing fluid costs were respectively saved 50% and 30% and the initial daily production and 2 years’ cumulative oil production were respectively increased 3.2 times and 1.6 times.Fracturing stimulation with different horizontal lengths were studied by NWM numerical simulation, and the results showd that with the increase of horizontal length, the initial daily production and the cumulative oil production were increased significantly, and the decline rate was reduced. Therefore, extended reach horizontal well fracturing technology was proposed. In order to solve the blocking problem when tripping long fracturing string into extended reach horizontal well with openhole completion, 3 combined arc sections mathematical model was established, and successfully carried out in fracturing wells’ pilot tests and the result showed that the technology saved 22% total well costs, and increased 1.6 times initial daily production, and NPV10 increased 86%. |
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