Research On Deoilling Process Of Waste Oil-based Drill Cutting And Purification Of Recycled The Sump Oil

As the need of production process,the oil-based drilling fluid are usually used in the oil and gas field drilling process.The oil-based drill cuttings with black mud-like and covering by oil-based drilling fluids are produced.And oil-based drill cuttings belong to hazardous wastes.Do nothing direct emissions,caused great harm to the environment.So far,oil-based cuttings have not more appropriate treatment method.And the oil-based drill cuttings samples form a southwest oil and gas company.This research based on the analysis of its physical and chemical indicators,using the technology of hot chemical washing realized base oil separation.And the recycled sump oil were purified by means of solvent extraction method.The influencing factors are optimized,and the optimum parameters are determined.The enlarge experiment of hot washing process treat oil-based drill cuttings and industrial design are done.Specific conclusions are as follows:(1)Oil-based drill cuttings are disposed by hot chemical washing.The each agent in deoiling agent effect on deoiling effect by orthogonal experiment is tested : base oil stripping agent > wetting reversal agent > penetrating agent;suitable dosage: base oil stripping agent S 0.5 g/L,wetting reversal agent CTAB150 mg/L,penetrating agent OT 50 mg/L.Processing parameters are optimized by single factor experiment,examines the effect of temperature,p H,time,washing times,deoiling agent and oil-based drill cuttings quality ratio and centrifugal conditions on deoiling process.Tests revealed that: adjusted the pH of about 4,deoiling agent and drill cuttings quality ratio is 3 ? 1,washing temperature is 50?,washing time is 1.5 h.After the separation of base oil,the oil content in residue is lower than 1 %.At the same time,the separation of liquid can be recycled for new oil base drilling cuttings dilution.(2)The recycled sump oil are purified by the solvent extraction.To contrast optimal experiment and processing parameters are optimized by single factor experiment,examined the effect of extraction temperature,extraction time,extraction times,mass ratio of extraction agent and the sump oil on the purification process.The result showed that petroleum ether(60~90)as extraction agent of purification of sump oil.At room temperature the extraction are tested,sump oil quality is half of extraction agent quality,extraction time 120 min,extraction times is one.After the treatment,in the process under the condition of oil refinery purified the dirty oil ash content about 0.028%,moisture content was not detected,meet the needs of recycle.The process conditions of the purification of oil recovery rate of 84.8 %.The extracting agent of the purification of sump oil is recovered by atmospheric distillation,the recovery temperature of petroleum ether is 85 ?,the recovery is about 80 %.The processing cost is estimated,the cost of purification of sump oil is about 26 ?/L.(3)The enlarge experiments of the optimal process parameters of hot washing process treated oil-based drill cuttings are done,the results showed that,after the treatment,the oil content in residue is lower than 1 %,and the treatment effect is nice.According to the optimal process parameters of the hot-washing method to dispose the waste oil-based cuttings and the results of the enlarge experiments,process of the deoilling unit is designed and the processing cost is estimated.The cost of the direct operation is about 49.75 ?/t and the cost is relatively low,provides a certain basis for engineering promotion.Economic benefit calculation shows that the treatment of waste oil-based drill cuttings,the processing cost of1,500 ?/t,and the output of 1000 t/a,by hot washing and purification treatment with petroleum ether,the income of 198,000 ?/t.It will has a great deal of real economic benefits.