山东东营车镇凹陷古近系流体异常高压及其对深层碎屑岩储集层的影响

受流体异常高压影响而发育的异常孔隙(砂)砾岩储集层成为深层油气储集层和油气勘探研究的热点之一.测井、钻井及试油结果揭示,车镇凹陷古近系沙河街组广泛存在流体异常高压,且与(砂)砾岩储集层含油性及产能具有密切关系.在试油地层压力实测数据标定下,利用测井资料等效深度法对古近系沙河街组分层系、分地区进行了地层压力计算.计算结果...     

泊松阻抗地震属性在刚果A区块油气检测中的应用

叠前地震反演是根据振幅随炮检距或入射角的变化规律所反映的地下岩性和孔隙流体性质,来预测油气和估计地层岩性参数的一项技术,但直接应用叠前地震反演的结果还存在反演的属性随着地层埋深的增加而存在明显的压实背景趋势的影响,以及分析描述储层孔隙内流体特征时,经常存在单个属性难以有效识别孔隙内流体类型的不足。泊松阻抗是由叠前地震反演结果推导出的属性,它将泊松比和密度两种属性融合为单一的泊松阻抗属性,其泊松阻抗属性有助于实现将含油气储层从围岩中进行有效分离,达到识别砂岩孔隙内流体的目的。将泊松阻抗作为一种新的油气检测地震属性应用于西非深水勘探区块的烃类检测中,其钻前预测与实钻结果完全一致,从而证实了泊松阻抗钻前预测油气的可靠性和准确性,取得了较好的应用效果,显示了泊松阻抗作为一种新的油气检测地震属性的独特作用。     

应用贝叶斯最佳二次型判别函数识别油气水层

准确地判断测井剖面中的油气水层,这是油田一项十分重要的工作。解释油气水层始终是对整个油田地质情况的不断认识过程。由于油田地质情况的复杂性,由于各种测井资料只能间接地反映岩层性质的某一个侧面,因此,至今没有一种测井方法能够单独地准确地指出地层内含有的流体性质:即孔隙内是含油,还是含水,或者油水同层以及干层。     

一种适用于欠压实成因的地层孔隙流体压力预测技术

为了提高基于欠压实成因机制的地层孔隙流体压力预测的准确性,这里从提高地震层速度场的计算精度的角度出发,提出了一种高精度地层孔隙流体压力预测技术。①该技术针对浅部地层(无测井曲线的地层段)采用三维约束DIX反演方法和叠加速度体、层位数据计算浅部地层的地震层速度体;②针对中深层地层(有测井曲线的地层段)采用叠后波阻抗反演方法和叠后三维地震数据体、测井数据、层位数据计算中深层地层的地震层速度;③沿着研究区的某一浅部地层分界面将浅部地层与中深层地层的地震层速度体进行拼接处理,得到一个完整的地震层速度体;④采用"Fillippone方法+Eaton方法"的组合方法进行三维地层孔隙流体压力预测。某区页岩气地层的实际计算结果验证了该技术的正确性与可靠性,其预测的地层孔隙流体压力与实钻井一致,且目的层的地层孔隙压力平面分布特征与地质认识一致,有助于指导研究区后续的勘探与开发。     

碳氧比能谱测井解释油气水层的方法基础及油田应用实例

碳氧比能谱测井是一种探测地层化学指示元素比值的核测井方法。根据测量的碳氧比(C/O)和硅钙比(Si/Ca),可以确定套管井地层含水饱和度及其产水率。从80年代起,我国大庆、胜利、辽河、大港油田先后开展了碳氧比能谱测井,在套管井地层中找油找气,获得了显著的地质效果。本文论述碳氧比能谱测井解释油气水层的方法基础及油田应用实例。     

多场耦合作用下致密储层渗流特性研究

储层岩石的渗流特性对致密砂岩储层的评价及开发具有重要意义。为此,研究构建热流固耦合控制方程,采用COMSOL Multiphyics软件,针对准噶尔盆地中部4区块某三维区致密储层不同开采时间下流体渗流速度和地层孔隙压力的分布规律开展了数值模拟研究。研究结果表明,流体渗流速度最大值出现在井口及其周围地区,断层破碎过渡带流体渗流速度高于周围连续地层和断层核部;随着与井口距离的增加,开采过程中流体渗流速度变化规律由先增加后减小最后趋于稳定逐步转化为先缓慢增加后逐步趋于稳定;在开采初期,孔隙压力等压线在井口周围呈环形分布,而后低应力区沿断层的开展方向进行扩展;孔隙压力随着开采时间的增加而不断减小,同时间节点下,距离井口越远,孔隙压力越大且下降幅度越小。研究成果为正确预测开发生产指标,为提高致密油气勘探开发效果提供技术支撑。      

鄂尔多斯盆地环西—彭阳地区长8段储层流体性质测井判别方法

鄂尔多斯盆地环西—彭阳地区长8段储层蕴含丰富油气资源，但储层非均质性强，孔隙结构复杂，且受异常低压、黏土矿物附加导电以及高束缚水饱和度影响，油水层分异差，测井响应特征差异不明显，流体性质识别难度大。本文通过岩芯薄片观察、常规测井等资料，对长8段储层四性关系等进行了研究，结果表明长8段岩性主要是中、细砂岩，平均孔隙度14. 68%，渗透率7. 13×10-3 μm2。在此基础上引入视地层水电阻率作为有效参数，建立RwaAC交会图版，该方法考虑了不同储层物性的差异对储层电性的影响，克服了储层孔隙结构复杂因素的影响，突出了含油气信息，能有效识别不同的流体类型，通过该方法实现了12口井70个层位流体性质测井判别，与试油资料验证良好。研究成果对于长8段储层测井评价和油气勘探开发具有指导意见。     

松辽盆地深层孔隙流体压力预测

孔隙流体压力属于流体状态参量, 它是进行盆地动力学分析、油气成藏动力学分析以及油气预测的重要因素之一.孔隙流体压力的预测模式应尽量将各种地质作用对其的贡献考虑进去, 并且, 利用大量的实际地层测试参数与各种地球物理参数之间的相互关系来选择适当的数学模型.选用神经网络计算技术对松辽盆地深层孔隙流体压力进行了预测, 并对孔隙流体压力的可能成因进行了分析.      

地层抬升剥蚀对油气成藏贡献初探

含油气盆地普遍发育一个或多个剥蚀面,揭示剥蚀面的形成和油气藏的关系,不仅可以完善和发展已有的油气成藏理论,也必将对我国东部老油气区的勘探起到指导和促进作用。在对含油气盆地剥蚀次数和剥蚀量统计分析的基础上,建立了地层抬升剥蚀与油气成藏的空间和时间匹配关系;通过地质分析,从成藏机理的角度初步探讨了地层抬升剥蚀对油气成藏的贡献。统计分析和地质分析的结果显示:剥蚀层位本身或紧邻其下的层位就是储层;地层抬升剥蚀期多为油气聚集的时期;地层抬升过程中的流体温度降低及孔隙扩容可造成地层低压,从而为油气聚集提供动力,孔隙扩容还可为油气聚集提供更多的空间。     

新疆某三叠系低阻油气层特征及储层参数确定

随着新疆油气勘探开发工作的不断深入，不时出现的低电阻率油气层引起了人们的高度重视。为合理准确地评价这类油气层，开展了低阻油气层的测井资料解释和研究工作。什对新疆某油气田三叠系出现的低电阻率油气层，进行了油气层特征及测井曲线特征的描述，分析了低电阻车油气层的形成原因，并以此为基础，对流体识别，储层参数的确定及可靠性作了分析。     

On the frequency distribution of turbidite thickness

The frequency distribution of turbidite thickness records information on flow hydrodynamics, initial sediment volumes and source migration and is an important component of petroleum reservoir models. However, the nature of this thickness distribution is currently uncertain, with log‐normal or negative‐exponential frequency distributions and power‐law cumulative frequency distributions having been proposed by different authors. A detailed analysis of the Miocene Marnoso Arenacea Formation of the Italian Apennines shows that turbidite bed thickness and sand‐interval thickness within each bed have a frequency distribution comprising the sum of a series of log‐normal frequency distributions. These strata were deposited predominantly in a basin‐plain setting, and bed amalgamation is relatively rare. Beds or sand intervals truncated by erosion were excluded from this analysis. Each log‐normal frequency distribution characterizes bed or sand‐interval thickness for a given basal grain‐size or basal Bouma division. Measurements from the Silurian Aberystwyth Grits in Wales, the Cretaceous Great Valley Sequence in California and the Permian Karoo Basin in South Africa show that this conclusion holds for sequences of disparate age and variable location. The median thickness of these log‐normal distributions is positively correlated with basal grain‐size. The power‐law exponent relating the basal grain‐size and median thickness is different for turbidites with a basal A or B division and those with only C, D and E divisions. These two types of turbidite have been termed ‘thin bedded’ and ‘thick bedded’ by previous workers. A change in the power‐law exponent is proposed to be related to: (i) a transition from viscous to inertial settling of sediment grains; and (ii) hindered settling at high sediment concentrations. The bimodal thickness distribution of ‘thin‐bedded’ and ‘thick‐bedded’ turbidites noted by previous workers is explained as the result of a change in the power‐law exponent. This analysis supports the view that A and B divisions were deposited from high‐concentration flow components and that distinct grain‐size modes undergo different depositional processes. Summation of log‐normal frequency distributions for thin‐ and thick‐bedded turbidites produces a cumulative frequency distribution of thickness with a segmented power‐law trend. Thus, the occurrence of both log‐normal and segmented power‐law frequency distributions can be explained in a holistic fashion. Power‐law frequency distributions of turbidite thickness have previously been linked to power‐law distributions of earthquake magnitude or volumes of submarine slope failure. The log‐normal distribution for a given grain‐size class observed in this study suggests an alternative view, that turbidite thickness is determined by the multiplicative addition of several randomly distributed parameters, in addition to the settling velocity of the grain‐sizes present.     

NaCl胁迫对甜叶菊移栽苗生理生态特性的影响

通过盆栽法, 研究了不同浓度NaCl胁迫对甜叶菊移栽苗生理生态特性的影响. 结果表明: NaCl对甜叶菊移栽苗生长的胁迫表现为低促高抑的效应, 即0~44 mmol·L^-1浓度下, NaCl处理对甜叶菊移栽苗光合作用和生长具有促进作用; 44~140 mmol·L^-1浓度下, 甜叶菊光合参数、干叶产量、长势等逐渐下降; 大于140 mmol·L^-1浓度下, 甜叶菊将不能存活. 低浓度NaCl胁迫下, 甜叶菊叶生长量增加, 而茎和根的生长量与其他NaCl胁迫一样, 表现为增长量降低. 甜叶菊通过增加叶生物量适应低盐胁迫, 是甜叶菊叶子的增产新机制, 为生物量的分配研究提供了新的佐证. 此外, 所确定的Na⁺影响甜叶菊生长的低促高抑的浓度范围, 为今后甜叶菊规模化和精细化栽培种植提供了理论基础.     

Distribution of suspended sediment concentration in wide sediment‐laden streams: A novel power‐law theory

The diffusion equation of suspended sediment concentration in a wide sediment‐laden stream flow is dependent on the vertical gradient of streamwise velocity and the sediment diffusivity. This study aims at investigating the influence of the streamwise velocity laws on the suspended sediment concentration distributions, resulting from the solution of the diffusion equation. Firstly, the sediment concentration distributions are obtained numerically from the solution of the diffusion equation using different velocity laws and compared with the experimental data. It is found that the power‐law approximation produces good computational results for the concentration distributions. The accuracy of using a power‐law velocity model is comparable with the results obtained from other classical velocity laws, namely log‐law, log wake‐law and stratified log‐law. Secondly, a novel analytical solution is proposed for the determination of sediment concentration distribution, where a power‐law, wall‐concentration profile is coupled with a concentration wake function. The power‐law model (for velocity and concentration) is calibrated using the experimental data, and then a generalized wake function is obtained by choosing a suitable law. The developed power‐law model involving the wake function adjusted by an exponent predicts the sediment concentration distributions quite satisfactorily. Finally, a new explicit formula for the suspended‐load transport rate is derived from the proposed theory, where numerical computation of integrals, as needed in the Einstein theory, is avoided.     

冲积河流泥沙输移幂律函数指数变化规律

冲积河流泥沙输移幂律函数关系与不平衡输沙理论是对河道不平衡输沙同一物理现象的不同描述,两者既有区别也有联系。比较研究发现:对于恒定均匀流不平衡输沙过程,当输沙位于近平衡态时两者含沙量导函数表达式具有一阶近似等价性,当输沙远离平衡态时前者含沙量导函数中隐含考虑有泥沙恢复饱和系数的变化。基于两者等价性,推导建立了幂律函数指数计算表达式,表明指数随泥沙沉速、单宽流量和沿程距离而变化,且随着输移距离的增大呈指数衰减。基于前者含沙量导函数表达式结构特点,分析建立了相应泥沙恢复饱和系数变化的计算表达式。综合以上成果,改进提出了一种变幂指数的泥沙输移幂律函数计算模型。对库里·阿雷克沉沙池沿程断面输沙指数及含沙量计算结果表明,不同距离过水断面输沙指数的变化规律是合理的,含沙量计算值与实测值变化趋势基本符合。     

冻土与盐溶液系统中热质迁移及变形过程试验研究

用1.2MPa外载固结并冻结的高岭粘土与2mol浓度的氯化钠低温溶液相接触,由于冻土与盐溶液间的水势梯度,引起等温条件下,水分和盐分从溶液向冻土中迁移。冻土中部分区段由于含盐浓度增高,冰点下降、冻土融化并产生吸热效应。融化界面以上的冻土中,由于水分积聚,冰分凝,形成条带状构造并产生放热效应。冻土出现以冻胀为主的变形。水、盐迁移通量及变形量随时间按指数规律衰减并随外载增大和温度降低而减小。     

盐溶液对膨润土膨胀性的影响

膨润土因其优良的膨胀性和低渗透性常被用作深层地质处置库的缓冲和回填材料,但其膨胀性会受到地下流体溶液浓度的影响。针对这种现象,利用单轴固结仪研究了压实商用膨润土在不同上覆荷载和不同浓度NaCl溶液作用下的膨胀变形特性。结果表明：随着NaCl溶液浓度升高,该膨润土的膨胀性显著降低,且最大膨胀应变与上覆荷载之间在双对数坐标系下存在良好的线性关系。利用有效压力的概念和计算方法,实现了用唯一一条曲线来描述不同盐溶液浓度作用下膨润土的膨胀变形行为,同时证明了有效压力理论的合理性。     

杭州西湖初次换水观测结果的解释

为了适应杭州市旅游事业发展的需要,市政府开凿燧洞,引钱塘江水更换西湖湖水,改善西湖水质。湖水质量变差的主要原因是水中有机质和矿物质增加,即矿化度增高所致。而水的矿化度与其视电阻率呈近似线性关系,因此,对更换湖水的监测可用视电阻率法。从绘制出水等机电阻率图可以了解更换水(混合流)的动态变化;由于湖水物质浓度及其视电阻率变化遵守无限稀释作用规律,即负指数衰减规律,因此,可建立数学模型,从理论上揭示混合流的运动规律。最后,文章还从实测结果和数学模型出发,探讨了经济合理的换水方法。     

In situ AFM study on barite (0 0 1) surface dissolution in NaCl solutions at 30 °C

This paper reports in situ observations on barite (0 0 1) surface dissolution behavior in 0.1–0.001 M NaCl solutions at 30 °C using atomic force microscopy (AFM). The step retreating on barite (0 0 1) surfaces changed with increasing NaCl solution concentrations. In solutions with a higher NaCl concentration (⩾0.01 M), many steps showed curved or irregular fronts during the later experimental stage, while almost all steps in solutions with a lower NaCl concentration exhibited straight or angular fronts, even during the late stage. The splitting phenomenon of the initial 〈h k 0〉 one-layer steps (7.2 Å) into two half-layer steps (3.6 Å) occurred in all NaCl solutions, while that of the initial [0 1 0] one-layer steps observed only in the 0.1 M NaCl solution. The step retreat rates increased with an increasing NaCl solution concentration. We observed triangular etch pit and deep etch pit formation in all NaCl solutions, which tended to form late in solutions with lower NaCl concentrations. The deep etch pit morphology changed with increasing NaCl solution concentrations. A hexagonal form elongated in the [0 1 0] direction was bounded by the {1 0 0}, {3 1 0}, and (0 0 1) faces in a 0.001 M NaCl solution, and a rhombic form was bounded by the {5 1 0} and (0 0 1) faces in 0.01 M and 0.1 M NaCl solutions. An intermediate form was observed in a 0.005 M NaCl solution, which was defined by {1 0 0}, a curved face tangent to the [0 1 0] direction, {3 1 0}, and (0 0 1) faces: the intermediate form appeared between the hexagonal and rhombic forms in solutions with lower and higher NaCl concentrations, respectively. The triangular etch pit and deep etch pit growth rates also increased with the NaCl solution concentration. Combining the step and face retreat rates in NaCl solutions estimated in this AFM study as well as the data on the effect of water temperature on the retreat rates reported in our earlier study, we produced two new findings. One finding is that the retreat rates increase by approximately two-fold when the NaCl solution concentration increases by one order of magnitude, and the other finding is that the retreat rate increase due to a one order of magnitude increase in the NaCl concentration corresponds to an increase of approximately 8 °C in water temperature. This correlation may help to understand and evaluate increasing dissolution kinetics induced by the different mechanisms where barite dissolution is promoted by the catalytic effect of Na⁺ and Cl⁻ ions (through an increase in the NaCl solution concentration) or by an increase in the hydration of Ba²⁺ and SO₄²⁻ (through an increase in water temperature).     

溶液矿化度及加量对钠-蒙脱石晶间距的影响研究

自来水引起的钠-蒙脱石黏土矿物晶间距增量大于不同矿化度的KCl、NaCl、CaCl2溶液,在水中加入不同类型的盐有助于稳定钠-蒙脱石黏土矿物,抑制黏土矿物晶间距扩展。不同类型、不同矿化度盐溶液引起的钠-蒙脱石黏土矿物晶间距增量不同,比较KCl、NaCl、CaCl2 3种溶液,KCl溶液引起的晶间距变化量最小,在饱和KCl溶液作用下,钠-蒙脱石黏土的晶间距变化量仅1.32%。钠-蒙脱石与不同类型溶液接触,随溶液加量增加,晶间距增量逐渐减小并逐渐趋于稳定。钠-蒙脱石的水化膨胀量与溶液总加量无直接关系,当黏土矿物浸泡在水溶液中时,晶间距不会随着水的总量增加而无限扩展。钠-蒙脱石与加量相同的不同类型溶液接触时,晶间距随接触时间增加呈复杂指数函数变化,表现出在初期突变增大并很快趋于稳定的特点。