碳酸盐岩油气层多级注入酸压—闭合酸化技术研究

对于低压、低渗碳酸盐岩气层 ,常规解堵酸化已解决不了问题 ,而越来越多地采用酸化压裂作为储层的重要改造措施。本文主要针对中原油田外围陕北探区渗透率小于 1×1 0 - 3μm2 的低渗碳酸盐岩气层 ,从多级注入酸压机理、闭合酸化机理及工艺实施三个方面对多级注入酸压—闭合酸化技术进行研究。拟通过该项技术的应用 ,达到提高气井产量 ,提高气田开发经济效益的目的     

大牛地气田动态分析方法

鄂尔多斯盆地大牛地气田开发进入了稳产阶段,动态监测工作已经积累了丰富的基础资料;但由于对常压低渗气藏生产动态分析方法的经验少,采用何种方法进行分析,是气田急需解决的重要问题。也只有通过合理的动态分析方法,有效的指导生产,才能寻求最佳的单井配产产量,使气井稳产高产,提高气井采收率。本文以大牛地气田地质研究结论为基础,讨论适合气田的动态分析方法。     

大牛地气田水平井钻井技术的运用

大牛地气田是是中国石油化工股份有限公司华北分公司开发地区之一,目前产能已建成年产量40亿立方米。该气田位于陕蒙交界地区,区块面积为2003.714km2,构造位置处于鄂尔多斯盆地伊陕斜坡东北部,储层分布特点是纵向上多层分布,自2005年开始投入规模开发,主要是以上古生界陆相沉积砂岩层和下古生界海相沉积的碳酸盐岩层为主,具有良好的天然气成藏条件,储层厚且面积大,资源丰富。气田主要产气储层物性表现为低孔、低渗。正是由于这种特点,导致直井开发产量低,经济效益差。因此,在大牛地区块水平井钻井技术的运用越来越广泛,产能越来越高;但对于钻井行业来讲,水平井施工所面对的技术难点仍有待改进。     

中石化大牛地气田钻井污水处理技术

根据中石化华北分公司大牛地气田钻井废水的实际情况,分析了污水的来源及特点。钻井废水主要包括钻井污水、压裂废液及其他作业废液。根据废水的水质特征确定了“脱稳—混凝—过滤“的处理工艺。生产运行结果表明:该工艺处理出水水质可达到国家《污水综合排放标准》要求。污水处理系统所投加药剂成本及运行成本适中,具有在类似油田推广应用价值。     

大牛地气田回注井地层水与注入水配伍性实验研究

大牛地气田W-4污水回注井地层水总矿化度大约为16500mg/L,水型为CaCl2型。该井在回注过程中,回注压力急剧升高,影响正常回注。针对该问题进行了地层水与注入水配伍性研究分析。结果表明:该回注井地层水对外来碱性流体有较强的敏感性;当pH=8时,地层水中出现红色Fe(OH)3沉淀,随着pH升高,红色Fe(OH)3沉淀不断增加;地层水与注入水以不同比例均匀混合不产生结垢、沉淀,两者有良好的配伍性。根据分析结果,提出了相应的措施,对于解决回注压力升高问题具有指导意义。     

大牛地气田采气工艺初探

大牛地气田具有多套气层叠合连片特点,且大部分为低产区块,气田中的太原组、山西组地层具有产水特征。受地层气产量较低的限制,大多数气井地层出水后无法依靠地层自身能量将地层水带出地面而无法连续生产。同时由于地层产水,极易在井口附近的油管内形成水合物和产生冰堵,严重地影响着气井采气的正常进行。通过研究与应用,较好地解决了大牛地气田的采气工艺问题。本文简要地介绍了大牛地气田的采气工艺。     

大牛地气田水平井压裂技术效果评价

为充分发挥大牛地气田产能,需对水平井进行压裂改造。通过对水平井压裂技术的优缺点进行分析评价,优选出适合大牛地气田的水平井压裂技术。     

大牛地气田地温数据测量和应用

大牛地气田位于陕西榆林市与内蒙古鄂尔多斯市交界地区。气田使用了集气站流程集气模式,气田冬季环境温度低至-30℃,需要在井口伴注甲醇预防堵塞。气井注醇量与温度关系较大,气田前期没有对管线埋深处温度进行测量,导致注醇量模拟值与实际不符。本文使用温度变送器,对气田管线埋深处温度进行了长期测量。并对地中温度的日、年变化规律进行了分析。测量的地中温度数据用于软件模拟预测气井进站温度和注醇量,预测结果与实际相符,能够指导气井注醇量调整。     

大牛地气田污水计量方法探讨

大牛地气田通过低温分离工艺进行气液分离,将分理出的污水通过罐车拉运至净化厂,回收污水中的甲醇及凝析油,并将处理合格后的污水回注地层。在气液分离-储存-处理过程中,用到了石英玻璃管液位计、金属管浮子流量计、磁致伸缩液位计等3种计量方式。本文对3种计量方式的原理特点进行了阐述,并对3种计量方式的精确度进行了对比分析,对气井污水计量方式提出了建议。     

大牛地气田钻井提速实践

大牛地气田储层特点是低压低渗低产,地层非均质性强、复杂情况多、地层可钻性差、砾石层多,以往的钻井工艺技术钻井周期长、机械钻速低、钻井成本高。因此,对钻井工艺技术进行研究,探索钻井提速,实现优质、高效、快速钻井,缩短了钻井周期、提高机械钻速和降低了钻井成本。     

大牛地气田甲醇回收工艺改造效果分析

针对大牛地气田甲醇污水处理站冬季塔底出水甲醇含量不能稳定地达到设计要求,分析了原甲醇回收工艺存在的问题,通过更换精馏塔塔板、重新设计并更换重沸器和其它设备以及对部分工艺流程改造后,使塔底水甲醇含量能够稳定在0.1%以下,满足回注水质控制要求,不但避免了对环境的污染,而且还取得一定的经济效益。     

大牛地气田中低压并管集输工艺试验研究

随着开发的持续深入,为了确保开发效益和开发决策,大牛地气田以33号低压集输实验站的试验平台,开展了低压集输综合实验研究。本文阐述了33号试验站的工艺优化及试验效果。     

挤出式污泥脱水装置在大牛地气田含醇含油污泥处理中的应用

在大牛地气田天然气开发过程中,产生大量含有甲醇、凝析油的污泥,为避免污泥污染环境,需使用专门的脱水设备处理污泥,降低污泥含水率,然后将污泥焚烧。经传统板框式脱水机、带式脱水机等脱水设备处理后的泥饼含水率在75%-85%之间,需要进行二次干化处理,而新型的挤出式污泥脱水装置处理后的泥饼含水率最低可降低到65%,无需进行二次干化处理,大大提高了污泥处理效率,同时也取得了较好的安全效益和经济效益。     

Prediction of gas flow directions in gas assisted injection molding when cavities and runners are involved

In the prediction of gas flow-direction for gas-assisted injection molding (GAIM), the statement“Gas goes to the direction of the last area to fill with resin”, has been accepted as a correct one. When there exists more than one area to fill with resin, a mold design engineer for GAIM technologies has to determine to which direction gas goes that commercial software for GAIM (e.g., Moldflow) may be utilized for its mold design. However commercial software is generally expensive and is sometimes hard to become familiar with. As a rule of thumb, it is suggested that the resistance to the initial velocity of melt polymer at the nearest geometry to a gas injection point should be used as its criterion since gas goes in the direction of least resistance to initial resin-velocity. Neither the flow rate nor the resistance to flow rate can be a criterion in the prediction. Thus the statement“Gas goes to the direction of the least resistance to flow rates”, should be corrected to“More flow rate goes to the direction of the least resistance to flow rates.”, The rule of thumb suggested in this paper was verified by using commercial software, Moldflow, in the prediction of gas flow directions in GAIM under geometries where cavities and runners were involved. When the ratio of initial resin-velocity is so close to unity it is proposed as the adapted rule of thumb to calculate new emerging resin-velocities and resistances to resin-velocity at the first coming change of diameters in series of pipes and to compare those for upper and lower sides each other to predict the gas direction. Thus the judgment as to which point is the point where gas starts to choose a preferred direction is very important in the prediction.     

气井生产系统节点分析在大牛地气田的应用

根据大牛地气田气井的实际情况,建立了与其适应的产能方程及井底压力的计算方法。应用节点分析方法,对大牛地气田生产气井进行IPR计算、井简流动计算、气嘴流动计算、节点分析计算、敏感参数分析等,对气井生产系统进行整体分析和预测,确定生产系统中各参数对整个系统的影响程度,优化了气井实际生产的生产参数。为选择合理的气井工作制度、确定油藏压力保持水平、优化采气方式提供了决策依据。加快了大牛地气田的开发进程,提高了气田开发经济效益。     

Flow directions in gas assisted injection molding when cavities of square flat plates and pipes are involved 2. Development of time-dependent flow model

For such conditions that (H/R₀)² is replaced by ε (that is the order of 10^-1) and is the order of one, the rule of thumb for an approximated flow model was introduced in part 1 of the paper to show, in qualitative way, whether the resistance of the relatively thick cavity of two square plates might affect the gas direction in GAIM under the aforesaid geometry. Subsequently, various simulations were performed by using Moldflow (version of MPI 4.0) under the conditions that all dimensions of cavity of two square plates and pipes were fixed except for the diameters of pipes, and the results of simulation were compared with the results of a rule of thumb (RT1) containing the approximated flow model as well as those of another rule of thumb (RT2) without the resistance of the relatively thick cavity of two square plates. There were some exceptional cases where RT1 or RT2 were not consistent with the simulation results (i.e., flow directions). Thus such a developed model as time-dependent model was required to describe transient behavior of the interface between gas phase and resin phase instead of comparison of initial velocities in upper side and lower side of the configuration, which was proposed and utilized to compare with the results of Moldflow in this 2 ^nd part of the paper. The predictions of the developed flow model were so quite consistent with the results of simulation that the proposed time-dependent flow model may be referred to describe very well the transient behavior of the movement of the interface of gas and melt-resin in the cavities. In addition, a timedependent model was also established and was used to compare with the results of Moldflow when cavities of pipes and runners were involved in configuration. It is amazing that the proposed developed model was able to predict exactly the cross-over between the trajectories of interface of upper and lower side, and it is also surprising to describe the time dependent behavior so well that the result of the predictions by the developed model were quite consistent to the results of simulation by Moldflow.     

Flow directions in gas assisted injection molding when cavities of square flat plates and pipes are involved 1. Theory of flow model and its criterion

In such a complex situation as the cavity of two square plates connected to cavities composed of four pipes with same length and different diameter connected in series and parallel, the resistance of cavity of two square plates should be combined with that of pipes to determine the gas direction in gas assisted injection molding (GAIM). The flow model of Newtonian fluid was previously suggested under the fan-shaped geometry incuding relatively thin cavity of two square plates when , and (H/R₀)².However, one may frequently encounter the problem of relatively thick fan-shaped cavity between two square plates where (H/R₀)² is around 10^-1 and is the order of one. The rule of thumb containing a first order-approximated flow model by perturbation technique was introduced to show, in qualitative way, whether the resistance of the relatively thick cavity of two square plates may affect the gas direction in GAIM under the fore-said geometry. Subsequently, various simulations were performed under the conditions that all dimensions of cavity of two square plates and pipes were fixed except for the diameters of pipes. The results of simulation were compared with the results of the rule of thumb (RT1) containing the approximated flow model as well as those of another rule of thumb (RT2) without the resistance of the relatively thick cavity of two square plates. The results of simulations were generally consistent with the former in qualitative way to determine gas directions in gas assisted injection molding even though a relatively large value of 0.36 was applied as the value of ε to describe a relatively thick cavity of two square plates. In addition, the situation was treated when cavities of pipes and runners were involved in configuration. The rule of thumb was used for the ratio of initial velocities to be recalculated at the first coming change of diameters when the ratio was close to unity and it was quite consistent to the results of simulation.     

苏里格气田东区二叠系盒8、山1段储层特征及影响因素

苏里格气田东区是苏里格气田外围一个具有很大天然气勘探潜力的区域。通过对苏里格气田东区二叠系盒8、山1段岩心、薄片资料、物性及压汞曲线特征等的分析,表明该区二叠系盒8、山1段储集岩以石英砂岩和岩屑石英砂岩为主,储集空间以次生溶孔和晶间微孔为主。属于低孔、低渗储层。并从沉积相、石英含量、成岩作用、微裂缝和砂体叠置分析了对储层的影响作用。储层物性主要受到沉积相和岩性的控制,成岩作用是影响储层优劣的决定性因素,微裂缝和砂体叠置在一定程度上改善了储层的孔隙度和渗透率。     

碳酸环己胺用于化工装备气相保护的研究

研究了气相缓蚀剂碳酸环己胺（CHC）用于化工装备保护的可能性。结果发现,CHC只要有饱和蒸气存在就可以提供良好的保护,而一旦脱离其蒸气氛围,即失去对金属的保护作用,并认为CHC属物理吸附型缓蚀剂。试验结果证明,CHC只能用于密闭体系,得出与目前普遍认为CHC可用于经常打开的包装体系相反的结论。