Countermeasures of sludge reduction and sludge source analysis in Yuanba gas field

The character of water production in Yuanba gas field became increasingly obvious, and deep analysis of the sludge source with study on the countermeasures of sludge reduction would become of great importance in high efficiency developing the gas field. Taking the sulphur-bearing waste water and residual liquid after pigging in Yuanba gas field as study objects, this paper optimized drug selection, reaction time, reaction conditions and reagent proportioning, meanwhile, for the goal of sludge reduction, the sludge pressure filtration equipment and rational allocation of sludge ratio was also optimized, considering the low desulfurization rate and high yield mud during the wastewater treatment. Experimental results show the mud in Yuanba gas field comes from the sulphur-bearing waste water after treatment and the residual liquid after pigging. The rate of water content of the sludge from the sulphur-bearing waste water could reduce to less than 50% by preliminary desulfured with vaporizing extract process deeply desulfurization with ZnCl₂ and filter pressing by filter frame sequently. The residual liquid after pigging can be emulsified in alkaline environment with compound demulsifier named EEA, which can be mixed with common mud producing from the sulphur-bearing waste water in a ratio below 1:2. In this way, the rate of water content of the oily sludge could be remained at 50%-55% after filter pressing by filter frame. The study in this paper can provide experimental demonstration and on-site guidance for sewage treatment and sludge reduction research in Yuanba gas field.