鄂尔多斯盆地为大型富油气叠合盆地,发育二叠系和三叠系多套页岩层系,陆相页岩气资源丰富.相比较于海相页岩,陆相页岩存在较多特殊性,其勘探开发面临诸多挑战,制约陆相页岩气难以实现经济开采,在地质特征、资源背景及勘探开发技术等方面对鄂尔多斯盆地页岩气勘探开发实践中取得的成果进行归纳,对目前的技术难点进行分析,以期在陆相页岩气发展进程中,有效利用机遇及时应对挑战.综合分析认为:延长探区陆相页岩厚度、有机碳含量、成熟度、含气量等参数达到国家标准规定的页岩气有利层段参数下限标准,具备页岩气成藏地质条件;陆相页岩气在宏观和微观非均质条件控制下,相态和规模上具有差异性富集特征,存在吸附成藏和吸附+游离复合成藏两类成藏模式,不同成藏机理指导陆相页岩气有利区优选及页岩气井生产.陆相页岩气勘探实践中形成多项关键配套工艺技术,建立起适用于强非均质性陆相页岩的测井评价方法,研发出适用于陆相页岩的水基钻井液体系和系列钻完井配套技术装备,形成CO2压裂技术体系和井场废液回收处理—利用技术.同时,面临精细“甜点”预测、钻井提速提效、压裂环保增效、降低成本等诸多挑战.目前中国陆相页岩气仍处于勘探开发初期,成本高,初期产量低,还需通过开展陆相页岩气勘探开发先导性试验,实现科技突破,形成资源接替,促进陆相页岩气产业取得经济效益.

近年来,虽然世界经济持续低迷,但中国的石油消费还是在稳步增加,石油战略储备也连年加速,因此,这就需要中国石油工业在世界的能源大河中加速向前.而频繁的油价波动直接影响到了中国石油工业乃至中国实体经济的发展,为此,研究油价波动对我国石油行业的影响具有现实意义.本文首先在对国际油价波动历史与现状分析的基础上,采用定量和定性相结合的方法分析国际油价波动的影响因素;其次从石油工业发展环境、投资和业绩方面分析油价波动对其影响,构建了国际油价与石油公司净资产收益率(ROE)的二次模型,结果表明油价在70～90美元/桶区间时公司效益最好,业务范围广的企业抗风险能力也相对较强;最后提出我国石油工业在此轮低油价下的应对策略.

在煤层气开发过程中确定储层渗透率是一个至关重要的因素,是有效评价煤层气井产能,合理安排生产制度,制定和优化开发方案的关键.而目前储层渗透率多是利用经验公式计算获得,或是停止生产重新测试,存在忽视生产过程中渗透率动态变化、影响生产等问题.本文应用渗流力学理论,结合煤层气实际生产特征,提出由生产数据反求煤层等效渗透率和裂缝渗透率的方法,通过编程计算等效渗透率评价煤层气压裂直井产能,裂缝渗透率评价煤层气井的压裂效果,并以延长煤层气实际生产数据进行计算求证,结果表明反求得到的渗透率能很好的匹配实际情况.

延长油田在开发过程中没有采收率经验公式,且石油行业标准的经验公式不适合延长低渗透油藏.基于此,采用SPSS软件多元线性回归方法拟合出4个采收率经验公式,为后续开展可采储量标定工作提供技术支撑.通过随机抽取区块对公式进行精度验证,平均相对误差为6.02%,证实了该公式综合拟合程度较高;在公式的选取中,发现不同的参数范围对应不同的经验公式模型;通过对新公式的分析,讨论了影响延长油田水驱采收率的主要地质和开发因素,孔隙度和原始含油饱和度对公式中采收率的贡献相对较大.

Schiff was synthesized with cinnamaldehyde and aniline.The inhibition action and comparison of Schiff base on N80 steel which immersed in 15％ hydrochloric acid solution was investigated by means of mass loss method and electrochemical test.The mass loss method result showed that corrosion rate could reduced to 1.637 2 g/(m2 · h) with 1.0％ Schiff.Schiff was anodic corrosion inhibitor,and was adsorbed on the surface of mild steel spontaneously.Furthermore,the adsorption of Schiff base follows Langmuir isotherm law.

Boron in fracturing flowback liquid could not only influence the reuse of guar gum fracturing fluid but also pollute environment.The boron in the fracturing flowback liquid which was pretreated through coacervation,chemical precipitation and filtration was removed using selective resin.The experimental results show that:when the fracturing flowback liquid with the pH of 8.0 and the solid to liquid ratio of 1:15 was stirred 30 minutes at 100 r/min,the mass concentration of boron decreases from 12.15 mg/L to 0.26 mg/L,and the boron removal ratio could reach to 97.86％.The performance of the slippery water fracturing fluid or guar gum fracturing fluid formulated using the treated flowback fracturing liquid accords with the technical requirement of SY/T 6376-2008.

Recently,an article with title of "A misunderstanding in provenance analysis:Sand changes of mineral,roundness,and size in flowing-water transportation" published by Professor Hu made a conclusion that,there is a paradox about changing of mineral,roundness,and size between phenomenon from modern river and conclusion from sedimentary petrology textbooks in China,which has been wrongly informed when used in source analysis based on Krumbein tumbling experiment and observation data.Based on former research,this paper holds that results from tumbling experiment shows indicative meaning to sand transportation from river.The results indicate that,as the transportation distance increases,sands get smaller and roundness gets better,and unstable components get less coupled with the chemical during the transportation.Due to the mixing action,the sands are mixed with those with various transportation distance in the transporting process,which leads to the changes of unstable mineral content,roundness and sand size.Textbooks of sedimentary petrology in China made description of the phenomenon mentioned above to different degree,which was widely recognized by a number of sedimentologists.However,it was not fully discussed in Professor Hu's paper published in 2017.Moreover,it seems improper for Professor Hu to determine the transportation distance only by geographic location.And there is no direct evidence showing roundness and sand size are transformed by river transportation.The observation with marked samples is recommended.

鄂尔多斯盆地陆相页岩气中生界储层地质条件复杂,钻井过程中易发生井壁失稳.根据库仑—摩尔准则,建立了大斜度井、水平井井壁坍塌压力计算模型,对延长陆相页岩气中生界储层大斜度井、水平井钻井过程中的井壁坍塌压力进行定量化研究,计算结果表明:钻井过程中井斜角超过50°左右,井壁坍塌压力将大幅增大,不利于井壁稳定;在井斜角小于50°的条件下,沿着水平最大地应力方位钻进时,大斜度井、水平井井壁坍塌压力最大;在井斜角大于50°的条件下,沿着水平最小地应力方位钻进时,大斜度井、水平井坍塌压力最大;延长陆相页岩气中生界储层在不同方位上钻井水平井的坍塌压力在1.18～1.26之间,为陆相页岩气井钻井工程设计提供了参考依据.

濮城油田沙一 下油藏经长期注水开发,综合含水高达98.7％,继续水驱提高采收率难度加大.为研究CO2/水交替驱在沙一下油藏的适应性,先进行岩心实验,进而利用油藏数值模拟评价其驱油效果,并对CO2注入速度、CO2段塞数目、交替注水速度和压力水平4个注采参数进行优化模拟.结果表明,濮城沙一下油藏注CO2最小混相压力18.4 MPa,地层条件能实现水气混相驱替,当注入倍数为1.28时,采收率达57.6％,比单独水驱采收率提高5.7％.选择CO2注入速度40.0 t/d,CO2段塞数目8个,水注入速度280.3 m3/d,压力水平18.8MPa作为最优方案参数,预测5年后含水率恢复到起始水平,采出程度能达64.6％.

Aiming at the shortage of water resources in the north of Shaanxi Province,coal& oil re-exploration result in groundwater contamination,and single mineral exploration situation of high investment,the coal and oil carried out an explora-tion in coordination can save water resources,reduce the cost of the investment,accelerate the exploration progress. Logging is a collaborative exploration of important technical means,according to comparison between the oil well logging and the coalfield logging,the article analyzes problems of the well logging data in the identification of coal beds,and thinks that it can use log-ging features of "high resistance,sound waves travel time,low natural gamma" to identify the coal seam,and at the moment of requirement,it can increase the precision logging series in Northern Shaanxi area.

伊陕斜坡作为鄂尔多斯盆地的主体部分,油气资源丰富,其中的主要生油层为中生界上三叠统延长组长7油层组.区域上,长7油层组的界定长期以张家滩页岩(K1)作为重要标志.而在靖边油区的某些地区,由于区域性标志的缺失,长7油层组的界定成为难点.以靖边油区测井曲线为基础,根据基准面旋回与测井相特征来界定长7油层组,即长7油层组发育于中期旋回的基准面较高处,为滨浅湖-三角洲环境.该方法划分的长7油层组,便于研究区域内等时沉积地层的发育,能够更好地与区域地质相联系,尤其与盆地沉积环境演化特征相匹配.

鄂尔多斯盆地陆相页岩气勘探潜力巨大,但对于陆相页岩气成因类型的研究相对滞后,限制了对页岩气的进一步勘探和开发.通过综合化学组分分析和碳、氢同位素分析的手段对伊陕斜坡东南部延长组页岩气和原油伴生气的地球化学特征及成因进行研究.研究结果表明延长组页岩气(生产气和真空解吸气)和原油伴生气都以烷烃类气体为主,其中甲烷含量都小于95％,非烃气体含量比较低.页岩解吸气中,非烃气体比例相对较高,且氧气含量异常高,这与解吸装置密封性不好或者装置本身残留空气清除不彻底有关.页岩气和原油伴生气的甲烷含量低、干燥系数(C1/C1-5)主要集中在0.6 ～0.9之间、C2/C3都小于3,δ13Ci值分布于-52.0‰～-44.9‰之间、δ13C2值都小于-29‰,δ13C3值都小于-25.5‰和δD1都小于-150‰,指示研究区页岩气和原油伴生气以陆相环境热成因的热解湿气(油型气)为主.页岩气和原油伴生气样品有相对高的正庚烷含量和正构烷烃(nC5-7)含量,δ13 C2值分布于-41.1‰～-31.1‰之间,说明延长组页岩气与原油伴生气都属于偏腐泥型天然气.此外,延长组页岩气和原油伴生气碳同位素系列基本都属正碳同位素系列,且δ13C1与δ13C2值,δ13C2值与δ13C3值有较好的正相关关系,这也表明页岩气和原油伴生气具有相同或相似的母质来源.

Capital asset pricing model and method of Weighted Average Cost of Capital(WACC)are introduced and adopted to measure shale gas project benchmark yield. Calculation process is as follows. Firstly,based on Rate of Equity(ROE)of U.S. shale gas companies and five-year deposit rate of domestic banks,by using capital asset pricing model,equity cost of capital on shale gas industry is calculated. Then,method of WACC is introduced to make quantitative measurement on the shale gas construction project’s benchmark yield. Finally,by considering the factors of domestic difficult-to-produce gas fields and social discount rate etc., it suggests that 8 % should be taken as the after-tax benchmark yield of shale gas construction projects.