为提高井筒压力预测精度和实时性,将无迹卡尔曼反演算法引入井筒压力预测模型中,建立了基于无迹卡尔曼滤波的井筒压力实时校正模型.该模型以无迹卡尔曼滤波为反演算法基础,以实测数据为输入参数,实时反演计算井筒摩阻校正系数,进而提高井筒压力预测精度和实时性.再分别使用井底压力模拟数据和井底压力实测数据对该模型进行研究.研究结果表明:建立的井筒压力校正模型不仅能够反演得到井筒摩阻校正系数,提高井筒压力预测精度,而且能够根据井下情况实时调整反演结果;利用摩阻校正系数能够提高井筒任意点压力和任意时刻井筒压力剖面预测精度,弥补井下工具单点测量的不足;模型预测精度受反演次数影响较大,模拟条件下,反演初始阶段,精度随反演次数增加而增加,反演次数达到200次后,反演精度趋于稳定.研究结果可预测井筒压力提供理论支撑.

水力振荡器是近年来应用较为广泛的提速工具,采用水力振荡器可以有效地消除水平井和大位移井钻进过程中的托压效应,提高钻井效率.鉴于此,设计了阀式水力振荡器.在工具结构设计和理论分析的基础上,结合流体力学原理,分析控制阀运动过程中受力特征,建立控制阀运动数学模型.通过算例分析了控制阀的运动特性,研究了波动压力和振荡频率的变化规律.研究表明:工具的波动压力峰值随钻井液排量和钻井液密度的增加而增大,随节流孔最小高度的增加而减小,而复位弹簧刚度和动阀质量对波动压力峰值影响较小;工具振荡频率随钻井液排量、钻井液密度、节流孔最小高度和动阀质量增加而减小,随复位弹簧刚度增加而增大.所得结论可为工具的结构设计和现场应用提供技术指导.

The multistage fracturing in openhole horizontal well is an effective technique for developing lowporosity,low-permeability and tight gas reservoirs.However,the low success rate of first-stage differential pressure sliding sleeve reduces the recovery rate.Based on the investigation and analysis of the differential pressure sliding sleeve in the multistage fracturing in openhole horizontal well,the reason of low opening success rate of the domestic differential pressure sliding sleeve is pointed out,i.e.the structural deformation and seal failure of the sliding sleeve.Therefore,based on the existing domestic differential pressure sliding sleeve,the structure of differential pressure sliding sleeve is improved using CAD and Solidworks software.The structure and sealing performance of differential pressure sliding sleeve are analyzed by ABAQUS finite element software.Finally,an indoor test is conducted to verify the rationality of the design.Modified differential pressure sliding sleeve improves the success rate of opening,which can improve the efficiency of oil and gas reservoir stimulation.

The heat exchanger network for crude atmospheric-vacuum distillation unit at shutdown condition of vacuum distillation unit is studied and an optimal revamping scheme is proposed.An Aspen Plus model of an atmospheric-vacuum distillation unit with a capacity of 5.0 million tons a year is developed,and the heat exchanger network under the shutdown situation of vacuum distillation column is simulated by Aspen Energy Analyzer.The pinch point analysis and energy utilization study of the heat exchanger network with the pinch point technology has found that the existing heat exchanger network has a great energy saving potential.On the basis of pinch point principles and assurance of appropriate temperature difference for heat transfer,the existing pinch point location of heat exchanger network and energy objective are determined,the heat exchange that violate the pinch-point rule are eliminated,the heat exchange process is improved and a new optimized heat exchanger network is obtained.On the basis of economic analysis of revamped heat exchanger network,an optimized heat exchanger network is recommended.After the operation of optimized heat exchanger network,the end temperature of crude oil after preheating is raised by 14.2 ℃,and annual utility saving is 12.8 MW;The total revamping investment is 1.6705 million Yuan (RMB) and the payback period is 3 months.The annual economic benefit is increased by 6.4637 million RMB a year.

储层地应力场是页岩气开发井网布置、井眼轨道设计、压裂设计的重要参考因素.其形成机理复杂,具有较强非均匀性,地应力的实测数据有限且具有局部性.为准确求取云南昭通黄金坝YS108区块页岩气储层的地应力场,通过研究分析储层地应力场的平面分布,利用多元线性回归方法求解页岩气储层地应力场,并在传统方法上增加三角分布载荷,模拟了储层非均质地应力,以提高地应力场的计算精度;同时建立页岩气储层平面的几何模型,利用Abaqus有限元软件和该区4口井的地应力实测资料,运用多元线性回归方法求解,得出了整个页岩气储层地应力场.结论认为:该方法计算精度较高,相对误差在8％以内,能较为合理地模拟出页岩储层的地应力场;根据得出的储层地应力场,水平井轨迹应沿最小主应力方向设计,压裂射孔位置应设计在最大主应力方向且两向地应力差较小的区域.

Oil and gas upward velocity is a very important parameter reflecting the activity of reservoir. During drilling,oil and gas upward velocity influences directly the safety of drilling operation. If not accurate,it is ease lead to accidents such as well kick,blowout and so forth,and cause the unreasonable drilling fluid density damaging the reservoir. The velocity obtained by using the method of lag time,which is widely applied during drilling,have higher error. Based on the analysis of the rule of oil and gas migration in the drilling fluid,a new calculation method was obtained. The method takes into account displacement effect of drilling tools,wellbore structure,BHA among other factors,and correctes the migration time of oil and gas. This method has been tested and the result shows that it has a high accuracy.

Modern precise managed pressure drilling technology proposes higher requirements on control accuracy of wellhead back pressure,but because of intense nonlinear relationship between pressure regulation characteristic and opening presented on throttle valve,it is difficult to achieve accurate regulation through single throttle valve within the scope of full opening for the current choke manifold.In the purpose of meeting the requirements of control accuracy of back pressure with traditional throttle valves,based on the research of flowing characteristic of parallel pipelines,this paper put forwards a thinking of realizing fine back pressure control by means of parallel choke manifold,and the pressure regulation characteristic of parallel choke manifold was analyzed by simulating the working process of parallel choke manifold with four branches that accurately control wellhead back pressure.Compared with the traditional choke manifold,parallel choke manifold has good linearity of characteristic curve on pressure regulation,larger regulation range,higher regulation accuracy,lower accuracy demand and longer service life of throttle valves and other obvious advantages,which have significant engineering meaning and economic benefit.This provides some technical references for further study on fine managed pressure drilling and ground control system.

A numerical simulation research was carried out of the gas-liquid two phase flow in circulation cyclone separators using Reynolds stress model(RSM), the distribution characteristics of the tangential velocity, axial velocity, radial velocity, pressure field, and Reynolds stress in circulation cyclone separators, and the trajectories of the liquid drop movements in the separators and the separation efficiency of the separators under the same inlet velocity, were discussed. The numerical simulation result shows that the tangential velocity had an obvious hump shape, the uplink and downlink flows of the axial velocity was clear, the radial velocity was comparatively slow, the pressure became gradually outward high, the distribution of Reynolds stress was complex and had not obvious laws, the efficiency of the separators was low for small-sized liquid drops, the influence of the inlet velocity on the separation efficiency was comparatively evident.

Super float valve(SFV)tray is a new type of trays developed by China University of Petroleum. SFV tray was designed with many innovation and optimization for valve structures combining the advantages of guide rectangular valve tray and micro V-grid fixed valve. The hydraulic and mass transfer performances of SFV were investigated with an air-water-oxygen system in a stainless steel column of φ1200 mm in comparison with the traditional F1 tray. Experimental results showed that SFV has pressure drop lowered by 10%—20%,weeping rate lowered by 20%—30%,entrainment lowered by 20% and mass transfer efficiency increased by 10%—20% as compared with F1. The industrial application showed that the high performance SFV tray could be used to the design and restoration of columns.

The paper presents the designing manner of the power factor detection of three-phase alternating current machine.It is counted by the phase difference between one-phase electric current and other two-phase voltage.The working principle of the designing manner is particularly illustrated.

It is necessary to detect the power factor in the course of electric power system management.The designing manner of the power factor detection of three-phase alternating current machine is presented.It is counted by the phase difference of angle between one-phase electric current and the same phase voltage.As HSI of single-chip-microcomputer of 80C196KC's external event is used to record the time when the current or voltage reaches zero,the power factor of three-phase system is given at high speed.The principle of mea-surement is particularly illustrated.The experimental result shows that this method has the feature of quickness and stability.

The fundamental principle and applications of acoustic emission technology are introduced briefly. The research findings and existing problems of the current researches on casing damage detection and prediction technology are also analyzed. So we can draw a conclusion that the technology of real-time monitoring on casing deformation remains blank, which is the important direction of technology development. Based on the analysis about the casing structure and related loads, a new theory about real-time monitoring of casing collapse with the acoustic emission technology is put forward. Also the complete set of laboratory equipment is established and the technical difficulty is analyzed. All the works give the theory and experiment basement for the real-time monitoring technology of casing damage.

At late stage of oilfield development casing failure is serious. Techniques for casing detection and prevention have been widely studied. The techniques for real-time monitoring of casing failure are new ones. A new theory is proposed that the principle of acoustic emission is used for real-time monitoring of casing failure and an experiment device is built for real-time monitoring of casing failure by using acoustic emission. A pilot test is conducted with simulation casings, it is demonstrated that the acoustic signal obtained in the deformation of simulation casing is corresponding to that of distortion and strain, the basic law of acoustic emission signal in its distortion is obtained, by which theoretical and experimental foundations would be laid down for studying of real-time monitoring of casing failure with acoustic emission technique.