Success Scope of Infinite Conductivity Fracturing Channels in Cambay Basin of India

摘要

Cambay is one of the oldest basins in India producing hydrocarbons since 1960's. It stretches almost 400 kilometers from south of Rajasthan to south of Gujarat in the western part of India and covering 53,000 sq. Km of total area. Cambay basin is contributing almost one-third of India's total onshore oil production. Raising production from Cambay basin is a considerable challenge as major producing fields are all Brownfield’s. Hydraulic Fracturing (HF) is in use since 1980's to stimulate and enhance production from average to poor quality sands of Cambay basin. HF leads to better production results and has helped in enhancing production from this region for a long time. HF success ratio in stimulating these reservoirs dwindled significantly in the last decade due to continuous exploitation and decrease in saturation and reservoir pressures in the area. Enhancing fracture effectiveness & conductivity and reducing pressure drop within fracture was key to overcome this challenge and take the production to the next level. Maximizing conductivity of proppant pack has its own inherent limitations and this led to the application of channel fracturing for the first time in India in the Cambay basin. Channel fracturing results in decoupling fracture conductivity from proppant pack conductivity and results in infinite fracture conductivity, longer effective fracture half-lengths & reduction in pressure drop in the fracture. Creating stable fracture channels is highly dependent on rock mechanical properties and first hand evaluation of this decides applicability of this technology in a particular field/sand. This paper discusses the production results of wells treated with open channel fracturing compared to production results of offset wells stimulated by Conventional fracturing technology. Then it sheds light on basic requirement and key factors to be able to decide applicability of this technology in a particular field/sand. In the end applicability of this novel technology in all the major fields of Cambay basin will be discussed with the overall scope of redevelopment of all the major brown-fields of India.