Abstract:

The key to unconventional oil and gas development, such as shale gas and tight oil and gas, is to improve quality and efficiency and reduce costs. This paper illustrates the adaptability of using local quartz sand instead of ceramsite as the mainstream proppant in the thin interbed tight sandstone of the L1 formation of the Fushan Oilfield, offshore Hainan, to optimize the fracture conductivity at low cost, and the laboratory test evaluation results of Hainan local 20/40 mesh quartz sand and 20/40 mesh ceramsite are provided. Under different stress and paving concentration, 20/40 mesh quartz sand and 20/40 mesh ceramsite have different conductivity; this further reveals the results of field tests conducted for two development wells with similar geological parameters on the basis of numerical simulation optimization tests. The fracture conductivity reaches 21 D·cm, which can meet the demand of tight sandstone reservoir in the L1 Formation. Under the stress condition of 35 Mpa, 10 kg·m^-2 laying concentration of 20/40 mesh quartz sand can obtain more than 21 D·cm conductivity. Field tests show that the quartz sand test well has the same effect as the ceramic test well in the early stage after fracturing. With longer production time, the cumulative oil production and stable production life of ceramsite well exceeded that of local quartz sand development well. Therefore, the economic benefits of ceramic-based proppant are higher and ceramic-based proppants are worth continuing to be used on a long-term and large-scale basis.

Key words: thin interbedded sandstone, replacement of ceramic by quartz sand, conductivity, proppant