Classification evaluation method for Chang 7 oil group of Yanchang formation in Ordos Basin

Abstract The Chang 7 oil group in the Ordos Basin has characteristics of a tight lithology, low formation pressure coefficient and strong reservoir heterogeneity. To better determine reasonable developmental technical countermeasures, oiliness, seepage capacity, compressibility evaluations are combined. Using combination field practice laboratory experiments, six types sweetness classification evaluation parameters screened: saturation, longitudinal layer structure coefficient, average pore throat radius, gas-oil ratio, brittleness index, minimum horizontal principal stress. By combining relationships among variables with initial production from directional wells, gray correlation method is used to quantify weights contributions production. On this basis, using difference for curve slope, constructed, it solves difficult problem quality provides reference basis optimal design well patterns fracturing reconstruction parameters.