The Study On Incineration Of The Waste Oil-based Drilling Cuttings

With the rapid development of China's oil and gas industry,the production of waste oil-based cuttings is also increasing,According to the ?Directory of National Hazardous Waste ?,waste oil-based drilling cuttings belongs to hazardous soild wastes.If it can not be disposed in time,it's urgent to dispose waste oil-based drilling cuttings.Via different ways to analyze the components of waste oil-based drilling cuttings,researched the combustion characteristics of waste oil based drilling cuttings,which provides the basis for the incineration disposal engineering design of the waste oil-based drilling cuttings.(1)Methods fit for analyzing the component of waste oil-based drilling cuttings were explored by simulated sample with known composition.The results show that the distillation is relatively appropriate to apply to the determination water content in waste oil-based drilling cuttings,Ash analysis method in the proximate analysis of coal can get the date of the rate of slag of waste oil-based drilling cuttings,while soxhlet extraction-infrared spectrophotometric method and incineration method is more accurate to apply to determination oil content in waste oil-based drilling cuttings.And with different measuring method,the definition of waste oil-based drilling cuttings oil content is different.So soxhlet extraction-infrared spectrophotometric method is suitable for the determination of total petroleum hydrocarbons,but incineration method is suitable for determination of total oil.(2)It comprehensively analysised the physico-chemical characteristics of the waste oil-based drilling cuttings,which includes p H,moisture content,oil content,proximate analysis,element analysis and thermal property analysis.The results show the extract pH of the waste oil-based drilling cuttings is between 8.5~ 8.8 and the oil content of waste oil-based drilling cuttings is 19.41 %,the slag content is 80.59 %,the moisture content is not measured,the ash content is78.48 %,the volatile content is 19.41 %,and the fixed carbon is 2.11 %.Waste oil-based cuttings have higher volatiles and play a major role in the incinerationprocess.The chlorine content of waste oil based drilling cuttings is 0.35 %,total sulfur content was 5.30 %,average total sulfur content of the combustible components was 1.25 %,it is similar to the sulfur content that of standard coal,and the nitrogen content was also low.The results indicated that gas emissions of nitrogen oxides and sulfur oxides were not lager by the burning of the waste oil-based drilling cuttings,and the rate of producing dioxins was low.The best method to determinate heavy metals in waste oil drilling cuttings is modified USEPA Method 3050.High calorific value of waste oil-based drilling cutting is8000 ~ 9000 J·g-1,so it can be stable combustion without auxiliary fuel.(3)Explore the combustion characteristics of the waste oil-based drilling cutting cutting.Results show that the weight loss process of burning waste oil-based drilling cuttings can be divided into three stages 100 ~ 300?,500 ~750? and 800 ~ 1000?,With the increasing of heating rates,degradation steps and peak position of DTG curve shifted to higher temperatures,and the corresponding rate of weight loss also increased.In the 100 ~ 300? and 500 ~750 ?,the petroleum substances of waste oil-based cuttings decompose into small molecules of hydrocarbons and water,the activation energy and the preexponential factor reduced.The oil material in the waste oil-based drilling cuttings is decomposed into small hydrocarbons and water precipitation during100 ~ 300? and 500 ~ 750?,the decompose of CaCO3,CaSO4 and other inorganic salt accompanied,hydrocarbons burn into CO2 and SO2 during 800 and1000?,at the same time,the formation of SO2 is concentrated in the 850?.Therefore,in the actual production process can be controlled below to 850? to reduce the pollution of SO2.The volatility of heavy metal element of burning waste oil-based drilling cuttings is Hg>As>Fe>Cu>Cr>Ni>Pb>Zn>Al.Heavy metals content in incineration ash of waste oil-based drilling cuttings is lower than GB15618-2008 "soil environmental quality standard" in the two indicators of the living,can be used to pave the way,building and backfill,realize recycling use in the end.(4)On the basis of the research on waste oil-based drilling cuttings and incineration characteristics,the incineration application scheme of waste oilbased drilling is put forward.Treatment of the waste oil-based drilling cuttings can bring better economic benefit and environmental benefit based drillingcuttings by incineration method.