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In the recent era of increasing oil and gas production, hydraulic fracturing is a proven economical technique to extract trapped hydrocarbons from tight reservoirs. A major factor associated with hydraulic fracturing is the significant quantity of proppant necessary and the high total contributing cost per well. For deep reservoirs, such as in the Middle East (ME), expensive, synthetic high-strength proppant (HSP) is necessary to withstand high closure stresses exceeding 15,000 psi. A new type of propping agent, a composite structure comprising low-performance sand from local sources in the ME, now exists that is capable of operating under these high closure stresses. Transforming low-performance sand into stable sand-based composite aggregates is a significant development, providing an abundant supply of low-cost propping agent that can enhance and sustain well productivity. This paper demonstrates the sustainable performance of novel thin sheets of the sand-based composite aggregates under application conditions. Analyses of the performance measurements illustrate the unique and necessary properties these aggregates should exhibit to be successful in hydraulic fracturing. Development of a new type of propping agent requires new techniques to measure performance. Most of these techniques apply common geophysical, chemical, and mechanical methods, while other techniques require considerable adaptation of traditional API testing methods. Performance of sand-based composite aggregates and synthetic HSP using these methods highlights the crucial and necessary aggregate properties. Laboratory simulation of a post-fracturing scenario showed that low-performance sand, after conversion into sand-based composite aggregates, can withstand high closure stresses up to 10,000 psi. The measured conductivity of the channels is significantly higher than traditional synthetic proppant packs, and the aggregates are sufficiently strong to avoid fines generation. These observations indicate that sand can provide an effective alternative to HSP, which allows successful hydraulic fracturing in regions where synthetic proppants are cost prohibitive. Finding an alternative to costly synthetic proppant has become more important in recent years. While the natural sand in the ME region is compositionally different and mechanically weaker than synthetic proppants and high-quality sands available in the USA, transforming the sand into composite structures provides unique performance properties. Because the sand is commercially abundant, this novel solution is a viable option. |
