Simulation Research on Coal-Water Slurry Gasification of Oil-Based Drill Cuttings Based on Fluent

In this paper,based on Fluent software,a five-nozzle gasifier reactor was established to simulate the gasification process of oil-based drill cuttings coal-water slurry.The influence of concentration and oxygen/carbon atomic ratio on the gasification process of oil-based drill cuttings coal-water slurry was investigated.The results show that when the oxygen flow is constant,the outlet temperature of gasifier decreases,the content of effective gas increases,and the carbon conversion rate decreases with the increase of concentration;When the ratio of oxygen to carbon atoms is constant,the effective gas content rises and the temperature rises with the increase of the concentration,and the carbon conversion rate reaches the maximum value when the concentration of oil-based drill cuttings coal-water slurry is 65%;When the concentration is constant,the effective gas content decreases and the outlet temperature rises with the increase of the oxygen/carbon atom ratio,and the carbon conversion rate reaches 99.80%when the oxygen/carbon atom ratio is 1.03.It shows that this method can effectively decompose the organic matter in oilbased drill cuttings and realize the efficient and cooperative treatment of oil-based drill cuttings.

Gas-hydrate formation,agglomeration and inhibition in oil-based drilling fluids for deep-water drilling

One of the main challenges in deep-water drilling is gas-hydrate plugs,which make the drilling unsafe.Some oil-based drilling fluids（OBDF） that would be used for deep-water drilling in the South China Sea were tested to investigate the characteristics of gas-hydrate formation,agglomeration and inhibition by an experimental system under the temperature of 4 ？C and pressure of 20 MPa,which would be similar to the case of 2000 m water depth.The results validate the hydrate shell formation model and show that the water cut can greatly influence hydrate formation and agglomeration behaviors in the OBDF.The oleophobic effect enhanced by hydrate shell formation which weakens or destroys the interfacial films effect and the hydrophilic effect are the dominant agglomeration mechanism of hydrate particles.The formation of gas hydrates in OBDF is easier and quicker than in water-based drilling fluids in deep-water conditions of low temperature and high pressure because the former is a W/O dispersive emulsion which means much more gas-water interfaces and nucleation sites than the later.Higher ethylene glycol concentrations can inhibit the formation of gas hydrates and to some extent also act as an anti-agglomerant to inhibit hydrates agglomeration in the OBDF.

Pyrolytic gas analysis and evaluation from thermal plasma pyrolysis of simulated oil-based drill cuttings

Oil-based drill cuttings(OBDCs)are hazardous wastes generated during shale gas exploration,and the rapid,efficient and safe disposal methods for OBDCs have attracted the attention of many researchers.Plasma pyrolysis technology is widely used in solid waste treatment due to its extremely high temperature and reaction activity.A laboratory-scale thermal plasma pyrolysis system was built to investigate the plasma pyrolysis mechanism of simulated OBDCs.The thermal decomposition characteristics of OBDCs were studied by thermogravimetric-derivative thermo gravimetric-differential scanning calorimetry(TG-DTG-DSC)analysis in the range of 50–1300℃.The thermal decomposition process of OBDCs was divided into the following four stages:evaporation of water and light oil,evaporation and decomposition of heavy oil,carbonate decomposition,and phase change reaction from solid to liquid.The effects of the oil ratio,water content,and water/oil(W/O)ratio of OBDCs on the composition and gas selectivity of pyrolytic gas were investigated.The results show that thermal plasma can crack the mineral oil in the OBDCs into clean gases such as H_(2),CO and C_(2)H_(2),while water can promote the decomposition of the heavy oil molecules and enhance the H_(2)production.The energy consumption model calculation for the pyrolysis and melting of OBDCs shows that the highest energy utilization and the lowest molar energy consumption of H_(2)were achieved at a W/O ratio of 1:4.Based on the thermal plasma pyrolysis system used in this study,the commercial application prospects and economic benefits of the plasma pyrolysis of OBDCs were discussed.

聚醚铵盐D230^(2+)协同脂肪酸萃取处理油基钻屑

以聚醚铵盐D230^(2+)协同脂肪酸,构建了一种新型开关溶剂体系,考察了该体系的开关性能以及对模拟总石油烃(TPH)的萃取分离效果,并将其用于油基钻屑(OBDC)的萃取处理。在聚醚铵盐D230^(2+)存在下,脂肪酸的亲疏水性可由CO_(2)/N_(2)可逆调控,实现TPH的分离和溶剂体系的回收。溶解度参数分析结果表明,月桂酸和肉豆蔻酸对TPH的溶解性最佳。以月桂酸为脂肪酸,在液固比6 mL/g、萃取温度70℃、搅拌转速400 r/min、搅拌时间40 min的优化条件下,OBDC残油率可达0.49%。4次循环萃取后溶剂体系的回收率仍保持在80.23%。聚醚铵盐D230^(2+)在界面的吸附改变了钻屑的润湿性,促进了重质组分的剥离,月桂酸溶解TPH并降低其黏度,二者协同实现了OBDC的强化萃取处理。

油基钻屑制备水泥熟料的试验研究

为实现页岩气行业可持续发展,推动油基钻屑的综合利用,解决油基钻屑环境污染问题,探索了以油基钻屑为原料制备水泥熟料的热工工艺及合理配方,选取6种不同配方的水泥生料在不同温度下进行了水泥熟料煅烧试验。研究表明,油基钻屑的矿物组分与黏土相似,经预处理后,油基灰渣可以作为水泥原料,但是掺入质量分数不得超过30%;以油基灰渣作为原料制备水泥熟料时,随油基灰渣质量分数的增加,水泥生料易烧性变差,煅烧温度降低,C_(3)S质量分数降低,C_(2)S质量分数增加;BaO对水泥熟料的烧成和矿物结晶状况影响较大,当温度为1300℃时,BaO掺量最佳值为1.5%,当温度超过1350℃时,随着BaO质量分数的增加,f-CaO的质量分数增加。