一种双叶轮动态旋流分离器的分离性能

采用数值模拟和实验相结合的方法,对研发的双叶轮动态旋流分离器性能进行系统研究。结果表明,随着涡板叶轮转速提高,装置分离效率逐渐增大,趋势逐渐平缓,最高效率可达97%以上;但是功耗会随着转速的提高呈指数增加,实验工况下推荐2100 r/min为最佳转速;涡板叶轮转速不变时,流量变化对腔体内部切向速度影响较小,使得处理量在50%~117%范围波动时,该水力旋流器都能保持较高的分离效率,效率变化在1%以内。研发的双叶轮动态旋流分离器具有分离效率高,抗流量波动能力强等特点,是一种高效的固 液分离技术。目前,相关技术装备已在我国南海文昌海上平台获得应用,效果良好。     

汽油典型烃分子氧化生胶机理的分子模拟

为深入认识汽油在使用过程中氧化生胶的反应机理,选取汽油中相同碳数的典型烃分子作为模型化合物,采用基于密度泛函理论的量子化学从头计算方法,建立了不同结构的汽油分子通过氧化链式自由基反应生成相对分子质量较大、极性较高的沉积物分子的反应网络。通过对比不同反应路径的反应能垒大小,得出容易氧化生胶的汽油烃分子的结构特点以及贡献生成沉积物的关键控速步骤和关键中间体,从而为抑制该氧化生胶过程提出关键措施。结果表明,汽油分子结构中存在双键α位C-H、叔位C-H或苯基α位C-H时,容易引发链式自由基反应,但能否继续向沉积物的反应方向进行取决于相对分子质量增大后的产物中是否仍然存在双键α位C-H、叔位C-H、苯基α位C-H或者C=O这种使得相邻C-H键变弱的吸电子基团。另外,在氧化生胶反应过程中,氢过氧化物（ROOH）和过氧自由基（ROO·）是最关键的2个中间体,抑制氧化生胶反应的关键在于清除它们。     

Experimental investigation of propagation mechanisms and fracture morphology for coalbed methane reservoirs

Fracture propagation mechanisms in coalbed methane (CBM) reservoirs are very complex due to the development of the internal cleat system. In this paper, the characteristics of initiation and propagation of hydraulic fractures in coal specimens at different angles between the face cleat and the maximum horizontal principal stress were investigated with hydraulic fracturing tests. The results indicate that the interactions between the hydraulic fractures and the cleat system have a major effect on fracture networks. “Step-like” fractures were formed in most experiments due to the existence of discontinuous butt cleats. The hydraulic fractures were more likely to divert or propagate along the butt cleat with an increase in the angles and a decrease in the horizontal principal stress difference. An increase in the injection rate and a decrease in the fracturing fluid viscosity were more conducive to fracture networks. In addition, the influence on fracture propagation of the residual coal fines in the wellbore was also studied. The existence of coal fines was an obstacle in fracturing, and no effective connection can be formed between fractures. The experimental investigation revealed the fracture propagation mechanisms and can provide guidance for hydraulic fracturing design of CBM reservoirs.     

Mineral composition and organic geochemistry of the Lower Cretaceous Xiagou Formation source rock from the Qingxi Sag, Jiuquan Basin, Northwest China

The Lower Cretaceous Xiagou Formation contains the major source rocks for the crude oils discovered in the Qingxi Sag and the South Uplift in the Jiuquan Basin, northwestern China. The Xiagou Formation source rock was formed in a closed, anoxic, reducing, alkaline lacustrine environment with a high salinity. Its high content of brittle minerals is favorable for the fracturing of reservoirs in source rock formations in the Qingxi Sag. The Xiagou Formation contains a great number of fair to excellent source rocks, and their organic matter (OM) came chiefly from plankton/algae and high plants as well as possibly bacterial organisms. The Xiagou Formation source rocks mainly contain Type II OM and some Type III and Type I OM, with good oil-generating potential. The source rock maturity is mainly in the early-mature and mature stages, and its R_o value corresponding to oil peak is about 0.8%, which is lower than classic oil peak Ro value of 1.0%; therefore, a great deal of hydrocarbon was generated before the classic oil peak R_o = 1.0%. Mature source rock in the Xiagou Formation tends to be distributed in the older members and at a greater depth. There is a better exploration potential of tight oil in the deep Qingxi Sag.     

利用偶极横波反射成像技术评价缝洞储层有效性

缝洞型储层有效性评价是深层油气勘探开发中面临的主要难题。对于储层中尺度较小的裂缝和断层,由于地震的分辨能力有限,而常规测井方法探测深度较浅,难以对该类地质特征进行准确评价。单井偶极横波反射成像技术能够有效利用低频横波的传播特点,对井旁20~30m范围内的声反射体进行成像。对偶极横波反射成像技术进行了深入研究,形成了从质量检测到空间反射体三维成像的全套处理流程和软件,提出径向—方位视图和径向—深度视图联合分析、偶极横波反射+微电阻率成像联合解释、井旁缝洞等地质构造产状交互拾取技术。该技术分别在碎屑岩地层和碳酸盐岩地层进行了应用,均取得明显应用效果,有效提升了缝洞型储层有效性评价的精度。     

致密油藏体积压裂水平井分区复合产能模型

水平井体积压裂是实现致密油藏有效开发的关键工程技术手段,对致密油藏体积压裂水平井产能的准确模拟计算为体积压裂参数优化设计和压后生产动态预测提供了参考。基于致密油藏体积压裂水平井生产过程中油藏的实际流动形态特征,将水平井划分三线性流区域,结合Warren-Root模型,考虑储集层启动压力梯度和天然裂缝的影响,建立了致密油藏体积压裂水平井分区复合产能模型。结合现场生产数据验证了模型可靠性,并对产能影响因素进行了分析。结果表明:压后总体产量受到延伸主裂缝的条数、半长和导流能力的影响;启动压力梯度及改造区的弹性储容比和窜流系数对压后中后期产量影响大;未改造区窜流系数和弹性储容比影响后期产量的递减速度。该研究对深化认识致密油藏体积压裂水平井流动规律,完善致密油藏体积压裂渗流理论,提升致密油体积压裂优化设计都具有重要理论意义和实际价值。     

渤海S油田聚合物驱合理产液指数降幅研究

为研究渤海S油田聚合物驱产液下降规律,进一步改善聚合物驱效果,运用油藏数值模拟技术,结合油藏动态分析,计算了不同条件下油井的合理产液指数降幅,并利用现场数据进行对比验证。结果表明:聚合物驱后油井产液指数下降具有普遍性,并受注聚合物时机、油井位置、周围是否有注水井的影响;注聚合物区块内,无水井干扰的油井合理产液指数降幅为30%~50%,有水井干扰时油井合理产液指数降幅为10%~30%,产液指数降幅位于合理降幅范围内的油井,聚合物驱效果较好。     

油田采出水中聚丙烯酰胺的生物降解

为了降低油田采出水中聚丙烯酰胺浓度,提高采出水处理效果,对菌株H3降解聚丙烯酰胺的条件进行研究。利用单因素实验方法考察了接种量、菌株活化次数、油田采出水培养基初始p H值、金属离子(Zn2+、Mn2+、Fe2+、Cu2+)等对聚丙烯酰胺的影响。结果显示:优化的菌株H3降解聚丙烯酰胺的培养条件为接种量2%、菌株活化3次、培养基初始p H值7.5,此条件下聚丙烯酰胺降解率可达38.4%;优化条件下,添加金属离子对聚丙烯酰胺降解具有一定影响,单独添加Zn2+、Mn2+、Fe2+离子对聚丙烯酰胺降解均具有一定的促进作用,单独添加Cu2+离子对聚丙烯酰胺降解具有一定的抑制作用;同时添加Zn2+、Mn2+、Fe2+离子显示出一定的协同作用,聚丙烯酰胺的降解率明显高于单独添加,降解率可达63.86%。     

管状激光介质的光学性质

针对管状激光介质的热透镜效应,提出“C1判据”和“热感应光线主轴”的观点;推导了二维光线矩阵和热透镜焦距;并指出提高光束质量的主要方法。     

周期性动态热效应光栅的研究

为使激光诱导动态光栅产生在空间上可分辨的高效率衍射光，光栅介质必须足够薄以满足光栅条件，但动态光栅自衍射效率却又随介质厚度的增加而增加，我们提出用相位匹配的周期性薄光栅组可解决这一矛盾，并在实验上用周期性热效应光栅对理论进行了验证。