A reserve calculation method for fracture-cavity carbonate reservoirs in Tarim Basin, NW China

Abstract

To avoid big deviation in reserve estimation and make scientific and reasonable reserves to guide the exploration and development of fracture-cavity carbonate reservoirs, a new three-dimensional reservoir space description and reserve calculation method for layered, fracture-cavity carbonate reservoirs is used to calculate the reserves of X block in the Halahatang oilfield in the Tarim Basin. In the method, the reserve calculation parameters are worked out by quantitative spatial delineation based on high precision three-dimensional seismic data; the high confidence well-seismic inversion and sensitive attributes and threshold value are used jointly to delineate the oil-bearing area, effective thickness and effective porosity of the cavity, vug and fracture reservoirs. The reserves are calculated with the volumetric method, and the dynamic recovery of different types of reservoirs is calibrated by actual drilling data. This method is suitable for reserve estimation and development program making of fracture-cavity carbonate reservoirs with strong heterogeneity. Key words: Tarim Basin, fracture-cavity carbonate reservoir, reserve calculation, quantitative space delineation, dynamic recovery, reservoir type