The Numerical Simulation Of Vertical Well And Multi-stage Fracking Of Horizontal Well In Tight Sandstone Reservoir

Anpeng Oilfield located in Tongbai county of Henan province. tectonic position in Zhaoao- Anpeng nose structure belt of Biyang Depression, oil field exploration in 1990, Bi 185 oil testing acquired industrial flows, and then find the Anpeng reservoirs. The buried depth of reservoir is 3000~3500m, the Formation is H3VII-IX oil group of the Tertiary. The porosity of H3Ⅶ、Ⅷ、Ⅸ oil field is range from 4% to 6%, the average permeability is 2.82×10-3μm2, reservoir developed fracture and micro cracks, belongs to fractured tight sandstone reservoirs.With the progress of technology level, the development of tight sandstone reservoirs mainly through layered fracturing of vertical Wells, multi-stage fracking of horizontal well, or massive hydraulic fracturing at present, in order to connected the natural fracture to improve the flow conductivity of the reservoir and the production capacity. According to the re-calculation in 2005, the oil in place is about 354.37×104t in Anpeng oilfield. The lower limit of porosity is set at 6%. If liberate the reservoir which porosity is ranged from 2% to 6% by multi-stage fracking of horizontal well, add the new-find reservoir, the total reserves is up to 5499×104t.By monitoring the field outcrop, directional coring, imaging logging, such as natural fracture recognition technology, determine the quantitative characteristic of fracture, the fracture system and occurrence, and study of the causes of cracks and control factors, then evaluate and forecast the cracks.According to Anpeng oilfield reservoir characteristics and the evaluation of fracture, established the pore-fracture dual media model. On the basis of modeling, the homogenization interception of single well do, then contrast the seepage characteristics in the streamline model of layered fracturing of vertical Wells and multi-stage fracking of horizontal well.By the history matching of volatile oil and condensate gas reservoir in Anpeng Oilfield, analysis of the distribution of remaining oil in the reservoir. Then evaluate the fracturing azimuth and length of horizontal section of horizontal well, the length of fracturing, the number of fracturing, the width and flow conductivity of fracturing, the morphology of fracturing, the vertical position of horizontal section, the development method, and the well spacing. At the same time, evaluate the layered fracturing of vertical Wells, including the width and length of fracturing, the conductivity of fracturing.Finally, compare the development effect of the layered fracturing of vertical Wells and multi-stage fracking of horizontal well, choose the well type and give recommendations.