Delineation of bed boundaries of array induction logging curves using deep learning

Delineation of bed boundaries based on resistivity logging curves is important prior information for the inversion and interpretation of resistivity logging data.Traditionally,the layering algorithm mainly use the derivatives of resistivity curves or other logging methods as reference.However,measurement error or resolution mismatch may lead to misjudgment of the boundary.In view of the shortcomings of traditional methods,this paper presents an automatic layering algorithm of array induction logging curves based on deep learning.In this algorithm,a locally connected convolution neural network is used,and the generalization ability of the network is improved by enlarging the training set,optimizing the window length and threshold,and strengthening the layering effect.Simulation and field data show the eff ectiveness of the proposed algorithm.

Inversion of Array Induction Logs and Its Application

With the help of the modified geometrical factor theory, the Marquardt method was used to calculate the true electrical parameters of the formation from array induction logs. The inversion results derived from the assumed model and some practical cases show that the rebuilt formation profile determined by 2-ft resolution array induction logs is reasonable when the formation thickness is greater than 1 m, which thus indicates that the inversion method is reliable and can provide quantitative information for the discrimination of oil/gas or water zone.

Numerical investigation of radio-frequency negative hydrogen ion sources by a three-dimensional fluid model

A three-dimensional fluid model is developed to investigate the radio-frequency inductively coupled H2 plasma in a reactor with a rectangular expansion chamber and a cylindrical driver chamber,for neutral beam injection system in CFETR.In this model,the electron effective collision frequency and the ion mobility at high E-fields are employed,for accurate simulation of discharges at low pressures(0.3 Pa-2 Pa)and high powers(40 kW-100 kW).The results indicate that when the high E-field ion mobility is taken into account,the electron density is about four times higher than the value in the low E-field case.In addition,the influences of the magnetic field,pressure and power on the electron density and electron temperature are demonstrated.It is found that the electron density and electron temperature in the xz-plane along permanent magnet side become much more asymmetric when magnetic field enhances.However,the plasma parameters in the yz-plane without permanent magnet side are symmetric no matter the magnetic field is applied or not.Besides,the maximum of the electron density first increases and then decreases with magnetic field,while the electron temperature at the bottom of the expansion region first decreases and then almost keeps constant.As the pressure increases from 0.3 Pa to 2 Pa,the electron density becomes higher,with the maximum moving upwards to the driver region,and the symmetry of the electron temperature in the xz-plane becomes much better.As power increases,the electron density rises,whereas the spatial distribution is similar.It can be summarized that the magnetic field and gas pressure have great influence on the symmetry of the plasma parameters,while the power only has little effect.

Initial outcome of induction chemotherapy followed by radiotherapy and concurrent weekly paclitaxel for stage Ⅲ non-small cell lung cancer

Objective： The aim of our study was to evaluate the toxicity and efficacy of induction chemotherapy （ICT） followed by three-dimensional conformal radiotherapy （3D CRT） and concurrent weekly paclitaxel on unresectable non-small cell lung cancer （NSCLC）. Methods： Stage III NSCLC patients with favorable conditions were treated with 2 to 4 cycles of carboplatin （AUC = 5-6, dl） combined with paclitaxel （175 mg/m〈 dl）, then followed by weekly paclitaxel （40 mg/m2） and concurrent 3D CRT within 3-4 weeks. The prescription dose was given as high as possible under the condition that V20 〈 31% and spinal cord dose 〈 50 Gy. Results： Thirty-one patients were enrolled. ICT was well tolerated. During the concurrent chemoradiotherapy, the treatment of 3 patients was ended ahead of the schedule because of severe pulmonary and heart toxicities; the treatment of 2 patients was delayed for 7 and 12 days because of fatigue. Myelosuppression was mild （16/31）： all were grade 1-2 except 1 was grade 3. Lymphocytopenia was more obvious （29/31, grade 3 in 21）. Three patients developed grade 3 radiation-induced esophagitis, and 2 developed grades 3-4 radiation-induced pneumonitis. Two developed grade 3 esophageal stricture. No grades 3-4 pulmonary fibrosis was observed. The overall response rate was 74.1%. The 1-, 2-, 3-year overall survival rates were 74.2%, 41.9%, and 34.6%, respectively, with the median survival time of 18.5 months. The 1-, 2-, 3-year local progression-freely survival rates were 64.5%, 32.3%, and 20.5%, respectively, with the median local progression-freely survival time of 14.3 months. Conclusion： The program of ICT followed by weekly paclitaxel and 3D CRT is accomplished in most of the favorable stage III NSCLC patients. The toxicity is tolerable, and the response rate is inspiriting.

扩展AL-log挖掘日志本体的ILP方法

为发现W eb使用记录中所蕴涵的用户访问模式,在深入分析日志本体中事件间的抽象关系后,提出适用于原子事件和复合事件间整分关系推理的ALC传播规则扩展已有的推理模式,并在此基础上提出一种挖掘日志本体的ILP方法。该方法结合描述逻辑和Horn规则在知识表示和推理过程中互补的特点,采用AL-log混合系统构建知识库,利用约束SLD-反驳消解和扩展ALC传播规则从日志本体中学习用户访问模式,达到站点商业智能和个性化的目的。最后给出验证该方法的实例,实验结果表明了该方法的可行性和有效性。

Analytical solution of electromagnetic field generated by induction logging tool in a fan-ring slot of drill collar while drilling

Based on the structural characteristic of metal drill collar for induction logging while drilling, we have given the analytical formulae of lengthways fields Ez and Hz when the tool is located in a fan-ring shaped slot of drill collar by the boundary conditions of electromagnetic field, and derived the other components of electromagnetic field in and out the fan-ring slot from Ez and Hz. In the other intervals of formation, where the drill collar is a solid cylinder, the analytical formulae of field are educed through the method of variable coefficient. The total analytical solutions of field in whole space have been obtained. With the help of the analytical formulae, we have also given numerical examples and analyzed the distributive characteristic of electromagnetic field. From the computational results we find that the secondary scattering field Hz is in a linear relation with the conductivity of stratum. The characteristic of field is very useful for induction logging while drilling, which can be used to measure and analyze the logging responses of the stratum conductivity. This paper sets up a theoretical foundation for us to study the distrbutions of field and to direct the design of logging instruments.

Integral equation of relationship on the apparent conductivity and true conductivity in induction logging

This paper investigates the relation between the induced electromotive force measured by induction logging tool and the apparent conductivity, and the relation between the apparent conductivity and the formation true conductivity. Assuming the conductivity in Green's function to be the function of the field point coordinate, the apparent conductivity expression of electric-field intensity is derived using Green's formula, and the integral equation has been established representing the relationship of the apparent conductivity with the true conductivity under this condition. The integral equation is analyzed and then leads to the conclusion that the equivalent conductivity is the apparent conductivity and the values of the apparent conductivity function contain the true conductivity, and the method derived the true conductivity from the apparent conductivity around the well axis is put forward. The validity of the approach given in this paper is verified through numerical calculation. On the basis of above means, the transmitter coil produces an electric-field distribution in formation at every point where the induction logging tool moves along a wellbore, and a number of the receiving coils obtain an apparent conductivity distribution; this is what induction electric-field logging is.

Preparation and characterization of three-dimensional micro-electrode for micro-supercapacitor based on inductively coupled plasma reactive etching technology

The capacity of supercapacitor charge storage depends on the size of the electrode surface area and the active material on the electrodes.To enhance the charge storage capacity with a reduced volume,silicon is used as the electrode material,and three-dimensional electrode structure is prepared to increase the electrode surface area on the footprint area by inductively coupled plasma reactive etching(ICP) techniques.The anodic constant current deposition method is employed to deposit manganese oxide on the electrode surface as the electroactive material.For comparison,samples without slot are prepared with a two-dimensional electrode.Scanning Electron Microscopy(SEM) and Energy Dispersive Spectroscopy(EDS) are used to characterize the surface morphology of the electrode structure and the deposited electroactive material.Electrochemical properties of the electrode are characterized by the cyclic voltammetry(CV) and the constant current charge-discharge method.Experimental results show that our approach can effectively increase the electrode surface area with more electroactive substances,and hence can increase storage capacity of the micro-supercapacitor.

Inductance calculation for 3D microsolenoids with single-layer coils

Three-dimensional(3D) single-layer microcoils have always been a key element for electromagnetic systems;but they lack an easy and accurate method to calculate the inductance value for their complex 3D micro-structures. This paper employed a curve-fitting process to obtain the associated equation for the inductance value and geometric parameters based on the simulation results. The correction factors regarding helical pitch and wire diameter were reviewed,which are used for compensation in the Nagaoka formula. The simulation process numerically simulated the performance of the 3D microcoils using a FEM electro-magnetic-coupled analysis method. Comparison of the simulated inductance value and the Nagaoka formula was undertaken,which shows that the helical pitch and wire diameter contribute a main role in the calculation error. The derived formula was expressed in a concise form to precisely calculate the inductance value of 3D microsolenoids with single-layer coils.

BASIC SOLUTION OF INDUCTION LOGGING THEORY

After Doll presented the well-known geometrical factor theory, Moran et al. fully discussed the propagation effect of electromagnetic waves in formation media and derived the rigorous solution based on the Maxwell equations. For a two-coil system model shown in Fig. 1, Moran et al. based their induction theory on the following point of view, i. e. the alternating current I_T in the transmitter coil T radiates electromagnetic waves in the sur-

THE APPLICATION OF SPLINE FUNCTION IN THE GEOMETRIC REPRODUCTION OF LOG SHAPE

The paper introduces a method to get three-dimensional reproduction of log shape by adopting Spline Function in fitting the curve of the finite log data. The method has ad-vantages of higher accuracy, less acquired data, easier to use, etc. Making use of high-precision drawing function of computer, the graphs of log geometric shape in different visual angles can be achieved easily with this method. It also provided a firm foundation for the determination of optimum saw cutting scheme.

LOGIQ阵列感应在测井中的研究与应用

论述了国内外测井技术中阵列感应测井的现状,介绍了哈里伯顿LOGIQ阵列感应测井仪器的组成和优势,以现场采集为例,分析了3点阵列感应测井资料的影响因素及资料把控,在长庆油田测井应用中取得了识别油气水层的显著效果。

高阻地层HDIL阵列感应影响因素分析与校正方法

近年来,四川盆地川中深层灯影组和龙王庙组天然气勘探中越来越多地使用油基泥浆,使得裸眼井电阻率测井只能选择阵列感应仪器。该地区目的层致密碳酸盐岩普遍表现为中高电阻率,典型气层的电阻率一般在500Ω·m以上甚至高达2000Ω·m,使得测量电导率的感应测井仪器接收的信号弱,叠加深层高温等因素的影响,采集的信号常出现负值,软件聚焦处理结果常出现平头现象,不能用于储层识别和气层评价。采用有限元模拟算法,分析泥浆电阻率、侵入半径及原状地层电阻率等单因素对阵列感应测井响应的影响规律,明确了各环境因素对感应测量信号的影响规律。结果表明,地层与泥浆电阻率对比度对测量信号有明显影响,当对比度接近于1时,各子阵列的误差较小,而侵入深度是另一个重要影响因素。总体上,较长源距的子阵列受各种因素的影响相对较小。针对实际资料的特点,提出一种基于Archie公式的原始电导率信号约束校正方法,对约束校正后的数据再开展软件聚焦,其结果得到明显改善。

基于二次规划的双感应测井反演方法

双感应电阻率反演由信号褶积测量原理,通过反褶积或正则化等线性方程组求解获得地层真实电阻率,对于准确求取储层含水饱和度具有重要意义。但传统的反褶积方法无法做到反褶积因子的准确计算,而Tikhonow正则化反演方法出现正则参数选择困难等问题。将反演问题转化为二次规划优化求解,并施加等式约束条件,可保证反演电阻率曲线的光滑性。目的针对等式约束的二次规划问题求解,方法本文基于神经计算原理和时间依赖的非线性动力系统,构造二次规划问题的递归人工神经网络模型,并采用改进Euler法同时模拟求解该模型的最优解和对偶问题解。结果现场实际应用表明,反演的地层电阻率有助于精准判断油、水层,相比原始测量电阻率,更加符合试油结果。结论基于二次规划的地层电阻率反演能够实现对地层原始电阻率的有效反演,具有较强的发现和识别油气储层的能力,可为油田的增储上产提供重要的技术支撑。

基于微扰法的裂缝发育层段的感应测井电磁场解析解

根据微扰法的思想,将裂缝的影响看作原状地层电磁场的微扰,在径向分层介质的亥姆霍兹方程解的基础上,研究了柱外无穷小天线振子电磁场的解析解,从而提出了一种适用于任意裂缝产状,以及任意井径、任意泥浆电阻率的感应测井电磁场的解析解法。据此,以中国常用的HDIL 1515 EA/MA阵列感应测井仪为例,计算了4种裂缝性地层模型中接收线圈的感应电动势,并绘制了视电导率曲线(理论图版)。研究表明,在裂缝发育层段,阵列感应视电导率曲线并不会出现“大幅度尖峰”的现象。同时,在油基泥浆条件下,微裂缝密集发育的地层段中,7个子阵列的视电导率曲线呈现出幅度差异,且其特征明显不同于泥浆侵入层段,可以作为微裂缝发育段的识别标志。

基于LSTM的小井眼阵列感应测井响应预测

快速准确地获取测井响应曲线是进行后续测井反演的基础。为了对测井响应进行高效的正演建模,将LSTM神经网络应用于小井眼阵列感应测井响应的预测中。数据集来源于COMSOL软件建模仿真得到的小井眼感应测井响应数据。在离线训练阶段,LSTM模型从测井响应数据库中提取到小井眼感应测井响应的数据特征。给定简单各向同性层状地层和复杂各向同性地层两种地层参数,训练得到的模型可用于预测阵列感应仪器的小井眼测井响应。研究表明,LSTM预测结果与基于测井响应数据库传统多维插值法的结果基本吻合。在保证预测结果精度的前提下,LSTM预测极大地提高了不同地层场景下测井响应的预测时间,且具有良好的泛化能力。

低渗透储层的径向电阻率特征及含油性——以鄂尔多斯盆地洛河油田延长组长6^(1)为例

鄂尔多斯盆地中部洛河油田长6^(1)低渗透油层含油饱和度变化大、油层非均质强,再加淡水钻井液侵入,造成油层电阻率径向分布不均且变化大。通过双感应-八侧向测井与阵列感应测井响应特征对比分析,认为水层的径向电阻率均为增阻侵入,油层、油水同层的径向电阻率普遍具有减阻侵入、低阻环带、高阻环带特征或相关趋势。其中,减阻侵入有助于识别高含油饱和度、高电阻率油层和油水同层,低阻环带和高阻环带有助于识别低电阻率油水同层。另外,部分油水同层的双感应-八侧向测井径向电阻率组合具有“增阻侵入”且深感应电阻率低的特征,推测可能是受双感应-八侧向测井探测范围限制,为低阻环带靠近井眼附近遭受淡水钻井液侵入影响的结果,深感应测井反映的是侵入带电阻率而不是油水同层的电阻率,容易被误解释为水层。因此,对于双感应-八侧向测井中具有“增阻侵入”特征且深感应电阻低值的储层,其流体性质有水层、油水同层这两种可能性,需要结合深探测测井资料或油藏地质特征进一步分析,以提高油层、水层的识别率。

水平井瞬变电磁边界远探测数值模拟与响应特征分析

为克服频率域电磁感应远探仪器过长的缺点,提出采用瞬变电磁远探测方法进行边界探测,给出了均匀地层中响应解析计算方法,基于COMSOL Multiphysics有限元数值软件,建立了层状地层水平井瞬变电磁远探测响应计算模型,并对其在地层界面识别时的响应特征进行了分析。结果显示:双对数坐标系下,均匀地层中瞬态电磁远探测响应随采集时间呈线性衰减规律,且地层电阻率越大,响应衰减越快,同时刻采集的响应值越小;在两层地层中,定义背景地层响应与层状地层响应差异为边界场响应,岩层边界会导致边界场产生局部极值,该极值点对应的时间与岩层电阻率对比度、探边距离以及仪器倾斜角度密切相关,增大收发线圈间距可导致边界场响应极值向晚期时刻移动;在三层地层中,瞬变电磁远探测响应同时包含岩层上边界和下边界的信息,在边界场响应中形成两个局部极值点。研究成果为瞬变电磁远探测打下良好基础。

感应测井技术的发展

许多井的钻进采用了油基钻井液或无钻井液(空气钻井)钻井,感应测井仪器被研发出来,提供了一种油基钻井液(非导电钻井液)或空气钻井井况下可以测井的一种方法;阵列感应测井仪采用一系列不同线圈距的线圈系测量同一地层,可以得出原状地层电阻率和侵人带电阻率,研究侵人带的变化,对电阻率进行径向成像及侵入剖面的成像;对于砂泥岩薄互层和裂缝性油气层,电阻率在水平方向的分量为低值,而在垂直方向测得的分量为高值。而现有阵列感应测井仪器,测量的电阻率只有水平分量,仅根据水平参数预测砂泥岩产层会出现错误或储层错失的情况,为得到更加精确的地层电阻率,推出了可多维识别地层特性的三维感应测井仪。本文结合较早应用的双感应仪器、正在使用的阵列感应测井仪、客户已经提出需求的三维感应测井仪情况,说明石油工业中感应测井技术的发展。

裂缝储层水平井双感应测井响应特征分析与认识

裂缝是油气的重要储存空间,电缆测井在直井中研究致密砂岩、碳酸盐岩等裂缝性储层较多。然而,关于水平井裂缝储层双感应测井响应研究较少,影响了水平井在裂缝储层的评价。由于水平井与直井工程环境不同,测井响应结果存在差异。为此,利用有限元方法建立水平井裂缝储层模型,对裂缝储层中的水平井双感应测井进行数值模拟分析。通过分析裂缝电导率与裂缝宽度、裂缝长度和裂缝弯曲度同时作用时的双感应测井响应特征,总结出不同因素对水平井双感应测井响应影响的规律。数值模拟结果可为水平井裂缝储层识别与评价提供技术支撑。