The technology of waterflooding to substitute oil in single well is the most economic method to reduce production decline in the exploration of fractured-vuggy carbonate reservoirs in the Tahe Oilfield. We deduce a waterflooding indication curve which is suitable for carbonate reservoir based on the definition of oil compressibility. We analyze the curve, and give some useful suggestions on the estimation of available geological reserves in single well, the time of waterflooding, the suitable work system and the method used to develop well potentiality. Our technology has been used for two years in oilfield, and it provides an effective foundation in the course quantitative analysis which is used to improve oilfield development effect.