Application of volumetric fracturing technology in Hongtai tight sandstone oil reservoir of low oil saturation

When conventional vertical well fracturing is applied in Hongtai tight sandstone oil reservoir of low saturation, its stimulation amplitude is low and stable production period is short, so it is difficult to realize the commercial production.In this paper, feasibility evaluation and implementation effect analysis of volumetric fracturing were adopted to realize stimulation, stable production and long oil production period of low oil saturation reservoirs.The difficulties of stimulation and stable production were solved by applying volumetric fracturing technology to create complex fracture networks.Fracturing mode and technological parameters were optimized to extend oil production period by identifying the primary factors (physical property and fracturing fluid volume) and secondary factors(proppant volume and average proppant concentration) that influence volumetric fracturing effect of Hongtai oil reservoir.In this way, the volumetric fracturing technology system for horizontal-well separate layer development was developed with fracturing fluid volume 600 m³/section, proppant volume 60 m³/section and average proppant concentration 22%.It is successfully used in field.Compared with the vertical well with the same physical properties, horizontal-well volumetric fracturing is 43.6% shorter in liquid discharge period foroil production, 47.4% higher in daily oil production and 25% longer in valid period.The research results can be used as the reference for the development of similar oil and gas reservoirs.