Abstract

The development of high-strength solidification process optimization research is of great significance for the resource utilization of oily and salty drilling waste, in response to the tight oil and gas drilling waste treatment needs. The orthogonal test method is used to optimize the high-strength curing formula with compressive strength as the evaluation index. Analyzing the hydration products and microstructure of the solidified material by XRD and SEM and analyzing the formation mechanism of the strength of solidified drilling waste. According to the orthogonal test, the best curing system formula is “100g waste+0.4g modifier+5gH₂O+19gMgCl₂+ 21g fly ash+28gMgO”. The best compressive strength is 39.65MPa at 28d and the treatment rate is 69.78%. The increase of NaCl, quartz, molding pressure and barite content can help increase the strength of the cured product, and the increase of the content of clay minerals and soaking will cause the destruction of the strength of the cured product. The high strength of the curing system is due to the formation of a hydration product 5Mg (OH)₂·MgCl₂·8H₂O mechanical interlocking structure in the composite curing system. The research results show that the high-strength solidification technology of tight oil and gas drilling waste can effectively promote the future development of drilling waste environmental protection technology.

Keywords:Drilling waste; Tight oil and gas reservoir; Orthogonal test; High strength curing; Environmental protection