Application Research Of Oily Cuttings In Asphalt Concrete Pavement

Oily cuttings are oil-bearing solid wastes formed in the process of shale gas drilling and development,with high oil content.However,it is difficult for mineral oil to degrade naturally in the environment,so the direct discharge of oil-based cuttings is bound to cause serious pollution to the environment.China's disposal of oily cuttings can not meet the requirements of environmental protection of high sewage charges,extremely strict management.At present,the disposal of oil cuttings at home and abroad is difficult to fundamentally solve the hidden danger of environmental pollution,and waste recycling has not been realized.With the vigorous exploitation of shale gas,more and more oil cuttings are generated.The safe and efficient treatment of a large amount of accumulated oil cuttings has become one of the important problems restricting the environmental protection production of petroleum enterprises.How to make the resource utilization of oil-base cuttings become the top priority.Based on the pretreatment of oil-base rock cuttings by shale gas drilling and development platform,this paper studies the mixing of pretreatment oil-base rock cuttings into asphalt concrete mixture for pre-drilling engineering asphalt pavement,so as to meet various technical indexes and road performance requirements of asphalt mixture,as well as national environmental protection standards.Based on laboratory test and theoretical analysis,the mixture ratio design and pavement performance of asphalt concrete mixed with oil-based rock cuttings are studied.The chemical composition and leaching toxicity of oil-based cuttings were determined.The mix proportion of asphalt concrete ac-13 mixture was designed.After replacing mineral powder with oil-based rock cuttings,the physical and mechanical indexes of the mixture were analyzed to determine the initial mix scheme.Five groups of asphalt concrete mixtures with different contents of oil-base cuttings were prepared,and various road performance tests were carried out to analyze the influence of oil-base cuttings on the road performance of asphalt mixture.Combined with road performance test results,the experimental study on cement modified asphalt mixture,the design of four groups of different cement dosage adding to the asphalt concrete mixture test,study the different cement dosage influence on water stability of mixture,determine the best dose of cement,determine the final oil-based debris mixed with asphalt concrete mixture ratio.Marshall Method,Road Performance Test and the analysis of the environmental impact assessment,with the increase of oil-based cutting instead of mineral powder proportion,decreased the water stability of asphalt mixture,high temperature stability and low temperature crack resistance,investigate its reason,oil-based cutting performance is poor in mineral powder,forming cohesion of asphalt mortar is reduced,cause mixture of middlings was in a terrible climate the adhesion force between material is reduced.The water stability of the mixture can no longer meet the requirements of the specification after all the oil-base cuttings replace the mineral powder.Therefore,the experimental study on the cement modified asphalt mixture was carried out and the optimal cement content was 2%.Finally,the mix design scheme that meets the requirements of road performance and national environmental protection regulations is determined.Through laboratory tests and theoretical analysis,oil-based cuttings can replace mineral powder as a filler for asphalt concrete mix,and a certain amount of cement needs to be added to modify the mixture.For the pre-drilling engineering well site road,the design of asphalt concrete AC-13 mixture is as follows: the mass ratio of 10~15mm gravel,5~10mm gravel,3~5mm gravel,0~3mm sand,cement and oil-based cuttings is 28:29:10:23:2:8,and the optimal asphalt dosage is 4.8%.The oil-base rock cuttings pretreated by the shale gas drilling and development platform are incorporated into the asphalt concrete mixture to be used in the asphalt pavement of the pre-drilling highway,so as to meet the road performance requirements of the pre-drilling highway and solve the problem of environmental pollution,and provide theoretical reference and scientific basis for the resource utilization of oil-base rock cuttings.Source control,local utilization and harmless disposal of oil-based rock cuttings as well as resource recycling are conducive to the sustainable development of society,environment and economy.