注水油田剪切套损机理研究与数值模拟

油田注水开发过程中,一旦注入水进入泥页岩夹层或断层带,将诱发大面积岩石顺层滑动.造成成片的套管变形或错断.渗流对油藏地应力场的影响在于一方面孔隙压力作为渗透力作用于岩体,另一方面表现为泥页岩的水化作用.基于Mohr-Coulomb准则和有效应力原理分析断层交界面岩石滑动机理,得到界面滑动时孔隙压力极值的估算方法.建立空间三维计算模型,并在泥岩夹层与砂岩储层中间加设一层接触单元,通过数值模拟得到注水压力对交界面岩层滑动及套管Mises应力的影响规律,为油田开采过程中防止剪切套损提供理论依据及合理计算方法.     

坪北油田套管损坏井治理技术研究

近年来,坪北油田套管损坏井的数量呈现快速增长趋势。套管损坏井不仅影响油水井正常生产、造成可采储量损失,而且存在污染洛河层水源的风险。目前套损井治理技术主要包括:膨胀管补贴与封隔器卡堵技术,由于工艺技术上存在一定缺陷,现场应用范围受限。因此,通过研究周边同类型油田的套损井治理技术,并积极开展适应性评价与先导现场试验,为指导下步坪北油田套损井的治理奠定技术基础。     

泥页岩地层水井套管载荷、临界注水时间确定

为研究泥页岩地层注水井套管损坏问题,建立了考虑地层蠕变载荷和地层膨胀应力影响的力学模型,在理论分析和数值计算的基础上得到了膨胀地层套管载荷规律.随地层膨胀系数不同,泥页岩地层中膨胀应力可达远场载荷的数倍至数十倍.提出了套管损坏的临界注水时间确定模型,发现极限注水时间与注入速度为反比例关系;极限注水时间与套管的极限载荷为线性关系.可为油田膨胀地层套管损坏的预测和控制提供切实的工程手段.     

周期注水渗流机理及其影响因素评价数值模拟研究

提出了一个适合于研究非均质油藏周期注水渗流机理的数值模拟模型，将微观剩余油储油可流动空间列为第二级渗流系统，采用两套空间重叠的网格描述油藏的非均质性。运用该模型模拟计算油水驱替运动过程，对比分析影响周期注水效果的油藏地质因素和人工注水方式参数，研究周期注水的驱油机理及适宜采用周期注水的油藏条件和合理的注水方式参数，为周期注水的决策及方式参烽的优化提供参考。     

牛圈湖油田超前注水非线性渗流数值模拟研究

在渗流规律实验研究基础上,建立了牛圈湖特低渗透油藏流体渗流的非线性渗流模型,通过数值模拟在超前注水油水井间建立有效的驱动压力梯度,确定了牛圈湖西山窑低压油藏合理的井距为200m、注采井距为150m和裂缝穿透比为0.5,通过对注采参数的优化模拟,确定地层压力系数达到1.1时油井投产为最佳时期.     

文中-文东油田套管损坏原因及对策

通过现场调查,应用数理统计方法对文中-文东油田套管损坏的原因进行理论分析,并对其采取提高钻井固井质量,做好防腐工作,在采油增产增注措施中严格实施套管保护及发展大修工艺技术等相应防治措施,可把套管损坏程度降到最低,减少水驱储量的损失.     

超高压地层组合套管的优化设计

国内许多油田深部地层的径向超高压，导致套管大量被挤毁变形，严重影响了油气的正常生产，针对这个问题，本文根据弹性力学中的厚壁筒理论和机械优化设计理论，提出了组合套管的优化设计方法。用该方法设计的组合套管，可有效地防止深部软岩地层的径向超高压所引起的套管变形或挤毁。     

水污染扩散的二维数值模拟及其可视化

针对城市公共安全应急平台的应用需求,建立了水污染扩散的二维数值模型,采用隐格式的有限差分法联合求解水动力方程和污染扩散方程,获得污染物浓度的时空分布,同时研究了基于GIS的水污染扩散模拟结果的可视化方法和途径.通过某河道水污染扩散模拟的实例分析,验证了模型及其算法的有效性和实用性,并在ArcGIS平台上实现了模拟结果的动态可视化,为水污染事故灾害应急处置和决策提供重要依据.     

天冬氨酸-谷氨酸共聚物用于油田回注水的试验

天冬氨酸-谷氨酸共聚物(PAG)是聚天冬氨酸的共聚改性产物,为了将其应用于油田回注水中,本文以吉林油田某采油厂回注水为介质,通过静态试验研究了PAG与缓蚀剂HEDP、杀菌剂ClO_2的配伍性,然后利用动态模拟试验对PAG复合药剂的综合性能进行了研究。试验结果表明,PAG阻垢性能优良,与HEDP、ClO_2具有良好的配伍性;当PAG、HEDP和ClO_2的质量浓度分别为12、36和2 mg/L时,复合药剂综合药效良好,满足回注水要求;PAG可作为阻垢剂用于油田回注水系统。     

Physical model test and numerical simulation on the failure mechanism of the roadway in layered soft rocks

To explore the failure mechanism of roadway in layered soft rocks, a physical model with the physically finite elemental slab assemblage(PFESA) method was established. Infrared thermography and a video camera were employed to capture thermal responses and deformation. The model results showed that layered soft roadway suffered from large deformation. A three-dimensional distinct element code(3 DEC) model with tetrahedral blocks was built to capture the characteristics of roadway deformation,stress, and cracks. The results showed two failure patterns, layer bending fracture and layer slipping after excavation. The layer bending fracture occurred at positions where the normal direction of layers pointed to the inside of the roadway and the layer slipping occurred in the ribs. Six schemes were proposed to investigate the effects of layered soft rocks. The results showed that the deformation of ribs was obviously larger than that of the roof and floor when the roadway passed through three types of strata.When the roadway was completely in a coal seam, the change of deformation in ribs was not obvious,while the deformation in the roof and floor increased obviously. These results can provide guidance for excavation and support design of roadways in layered soft rocks.     

Analysis of adiabatic shearing failure mechanism for aluminum matrix composites based on experimental and numerical simulation

Adiabatic shear behavior and the corresponding mechanism of TiB2/Al composites were researched by split Hopkinson pressure bar (SHPB).Results show that the flow stresses of the TiB2/Al composites exhibit softening tendency with the increasing of strain rates. All the composites fail in splitting and cutting with a 45 degree, and the phase transformed bands of molten aluminum are found on the adiabatic shear layers. The deformation behavior and shear localization of the TiB2/Al composites specimens were simulated by finite element code MSC.Marc. The Johnson-Cook model was used to describe the thermo-viscoplastic response of the specimen material. There was unanimous between the numerical result and the experimental result on the location of the adiabatic shear band. From the numerical simulation and experiment, it was concluded that the instantaneous failure of the composite was ascribed due to the local low strength area where the formation of adiabatic shear band was, and the stress condition had significant effect on the initiation and propagation of adiabatic shear band (ASB).     

分段多点成形技术及数值模拟

为了解决企业在成形设备的初投资及大型板类件的成形问题,在深入研究分段多点成形工艺特点的基础上,运用有限元软件ABAQUS成功地模拟了分段多点成形过程。采用非均匀有理B样条曲面(NURBS)完成了分段成形的关键环节———过渡区的协调设计,通过三维软件CATIA设计合理过渡区形状以消除板料的波浪形曲面缺陷,提高了工件的成形质量。     

Working mechanism and numerical simulation of assembly coastal building techniques

A new coastal technique, named as assembly coastal building, was introduced. The main concept of the technique was the assembling components which could be combined and locked together to form a large caisson. The assembly coastal building technique was used in a sea access road in Zhuanghai 4X1 well, Dagang Oilfield. The design plans and in-situ tests in the sea access road project were introduced in detail. According to the Zhuanghai project, the numerical simulation method of assembly coastal building technique was proposed. 2D numerical simulations were performed in FLAC to analyze the displacement and stability of the technique in the construction process and post-construction period. The settlement calculated is close to the in-situ results, which proves that the proposed numerical method is reasonable. Results show that the assembly coastal building technique has large safety factor under the gravity loading and wave loadings.     

采空区氧化带位置与注氮效果的数值模拟

为了对采空区易自燃危险区域进行划分,利用CFD方法对采空区氧气和漏风的静态分布、温度动态升温过程以及注氮下的氧气分布变化趋势进行了数值模拟.结果表明,"U"型通风工作面采空区的氧气分布在进风侧较回风侧更集中,易自燃危险区域主要位于进风侧氧气富集区域,范围大小从进风侧向回风侧递减;在氧化带略靠前的位置注氮,可以最大程度使氧气重新分布,防火效果较其他位置更显著.     

马王庙油田注水系统结垢原理与防护

油田投入注水开发后,注水系统容易结垢,严重影响地面注水系统运行和注水井吸水能力。通过对马王庙油田注水系统结垢原理分析,改善注入水水质、使用玻璃钢材料、改变管柱结构和采用新型缓蚀酸浸泡等防垢措施,较好地解决了马王庙油田注水系统结垢问题,相应改善了油田注水开发效果。     

基于瞬变反问题分析的给水管网漏失数值模拟

给水管网漏失问题亟待解决,而漏失的定点及定量是管网漏失控制研究的重要环节.为确定给水管网漏失点和漏失量,提出了基于水力瞬变分析的漏失数值模拟理论框架,指出该问题实质就是求解系统辩识反问题进行参数识别.首先设定漏失系数为系统待识别参数,并给出激励、响应以及二者间的传递模式.然后建立了反问题分析模型,应用特征线法计算雅可比矩阵,运用Newton-Raphson算法最小化压力测量值与计算值之间的偏差求解模型.最后通过算例管网阐明了数值模拟的具体步骤.