Although hydraulic fracturing is not a new technology, it has not yet been implemented in the United Arab Emirates. Abu Dhabi National Oil Company (ADNOC), the regional producer in United… Click to show full abstract
Although hydraulic fracturing is not a new technology, it has not yet been implemented in the United Arab Emirates. Abu Dhabi National Oil Company (ADNOC), the regional producer in United Arab Emirates, has set out to initiate the utilization of this treatment during year 2019. In this work, a systematic design procedure for hydraulic fracturing in tight petroleum-bearing reservoirs is proposed. The design caters for surface and subsurface flow parameters, and it is hoped to provide basic guidelines for ADNOC in this respect. The proposed design process incorporates both unified fracture design (UFD) methodology and the fracture geometry (PKN) model. Excel spreadsheets were developed and utilized to run sensitivity analysis for optimal performance and predict long-term production profiles before and after fracturing. The excel spreadsheets made are flexible in use, in the sense that they resolve issues with infinite/finite fractures, high/low surface injection rate as well as investigate for non-Darcy flow effects. Reliable published data were used to perform the necessary calculations. The results of the performance calculations have shown that it is possible to access commercial quantities of hydrocarbons from a tight reservoir. In addition, improved productivity by 15-folds and increased gas recovery of 1.02 MMMscf over the first 8 years of production can be achieved by proper hydraulic fracturing design and implementation in tight gas reservoirs. The results of calculations of non-Darcy effect revealed a threshold velocity of approximately 0.2 fps above which these effects could become significant in predicting the overall flow efficiency inside the fracture. To the authors’ knowledge, the literature has not fully addressed the hydraulic fracturing design analytically, and the methodology proposed in this work provides a complete design package which incorporates the UFD concept, the PKN model, the non-Darcy model, and long-term prediction of post-fracturing production performance, and applying the proposed approach in a case study.
               
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