Production Analysis of Multi-Stage Fractured Horizontal Wells in Tight Oil Reservoirs

Horizontal well is one of the main well types for oil production. Multi-stage fracturing of horizontal well has become the most effective means of exploiting tight oil reservoirs. How to further improve the stimulation effect of horizontal well fracturing has become the main challenge in oil and gas engineering. In this paper, the 21st tight oil Block of Ordos Basin Oilfield is taken as the research object to solve this problem, carries out the investigation of the geological conditions and seepage characteristics of the study area, a single well numerical model of multi-stage fractured horizontal well is established, and the effects of permeability, fracture length, conductivity, fracture spacing and distribution on oil well productivity are analyzed. The average reservoir thickness in the well area is 12 m, the average porosity is 0.22, the wellbore radius is 11.4 cm, and the effective average permeability is 0.083 mD. The reservoir is a typical reservoir with low porosity and permeability, with strong heterogeneity and sensitivity, and there are natural fractures in the reservoir; using the Eclipse numerical simulation software and the five-point method, the fracture seepage is divided into four stages: fracture linear flow stage, vertical radial flow stage, composite linear flow stage and quasi-radial flow stage. In the stage of staged fracturing of horizontal wells, with the increase of permeability, the production growth rate first rises and then decreases; with the increase of the fracture half-length, the production capacity of horizontal well staged fracturing showed a uniform increase, but the increase in production capacity basically remained unchanged; In the stage of staged fracturing of horizontal wells, with the increase of permeability, the production growth rate first rises and then decreases; when the total half-length of fractures is constant, The main fractures of the horizontal well gradually increase, and the total output of the staged fracturing of the horizontal well will gradually increase. The larger the value, the greater the contribution to the fracturing productivity of the horizontal well. The research results provide theoretical data support for improving the recovery of tight oil reservoirs.