| Popis: |
Controlling severe to total lost circulation in naturally fractured/vugular formations has always been challenging, particularly in carbonate formations across the Middle East. For such situations, conventional particulate lost circulation materials (LCMs) might not be effective. An extension to the work presented on a high fluid loss squeeze (HFLS) and reticulated foam LCM that provides further technical justification for making such LCMs more suitable for severe to total losses in uncertain situations is discussed. Savari et al. (2016) presented laboratory evaluation methodology, test results, and field applications of the subject HFLS and reticulated foam LCM. At the time, laboratory test data were presented for the LCM combination that could seal a laboratory-simulated fracture/slot size of 9,800 microns. For the current work, a similar test setup evaluated the efficiency of this LCM to seal larger openings. An adapter with an opening of 31,700 microns was used, and the combination of HFLS and reticulated foam LCM successfully sealed the opening when tested using an industry standard test setup. For laboratory-based tests, the combination of HFLS LCM and different-sized reticulated foam LCM was successful in sealing a 31,700 micron opening. An industry standard test setup [permeability plugging apparatus (PPA)] was used to evaluate the LCM. The same LCM combination was mixed in different bases, such as water, diesel, mineral oil, and brines; further, the LCM combination was weighted to determine if the sealing performance was consistent. For the aforementioned variations, the LCM combination was successful in sealing the 31,700 micron opening. The LCM plug was also evaluated for the maximum differential pressure it can withstand in wet conditions and for its compressive strength. Under wet conditions, the plug withheld 4000 psi differential pressure and yielded a compressive strength of approximately 400 to 2,800 psi. The latest test data were generated using industry standard PPA equipment with minor modifications. Hence, this helps provide an opportunity for end users to evaluate such LCMs in their own facilities to qualify and generate technical confidence in the LCM combinations before field application. The combination of HFLS and reticulated foam LCM can provide a technically efficient alternate to particulate solutions for managing severe to total losses in naturally fractured/vugular formations. Test data presented in this work are a first-of-its-kind reported in the petroleum industry literature for any comparable LCM, which further provides confidence in such LCM combinations and can help reduce well costs related to time and mud. |
