Abstract Development of the Tin Fouye Tabankort Gas Field, located approximately 600 miles South-Southeast of Algiers, was initiated in 1996 with the simultaneous start-up of surface facilities construction, workovers of existing wells and drilling of new wells, The evaluation of hydraulic fracturing operations was an important step in the formulation of the optimal development strategy for this complex Ordovician age sandstone reservoir. However, production performance and hydraulic fracturing design were uncertain due to large reservoir uncertainties (heterogeneity's, kh, skin, presence of natural fissures, etc.) and doubts about the fracture height growth behaviour.
To overcome these uncertainties, a complete set of measurements were performed including pre and post- hydraulic fracturing well tests, minifracturing on all wells including some bottom-hole pressure recording, temperature logs, and radioactive isotope tracing in both gel and proppant. Analysis of the collected data allowed a better understanding of reservoir characteristics, the influence of natural fissures on fracture design, and fracture growth behaviour. Indeed, results showed that the radioactive shale immediately above the IV-3 reservoir was often not a barrier to fracture growth.
With this knowledge, perforation and hydraulic fracturing strategies were steadily improved to maximize post-job production, and optimize project economics, Results proved to be very successful with the average production increasing by a factor of 5 at significantly reduced drawdown pressures.
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