Development and prospect of downhole monitoring and data transmission technology for separated zone water injection

This article outlines the development of downhole monitoring and data transmission technology for separated zone water injection in China.According to the development stages,the principles,operation processes,adaptability and application status of traditional downhole data acquisition method,cable communications and testing technology,cable-controlled downhole parameter real-time monitoring communication method and downhole wireless communication technology are introduced in detail.Problems and challenges of existing technologies in downhole monitoring and data transmission technology are pointed out.According to the production requirement,the future development direction of the downhole monitoring and data transmission technology for separated zone water injection is proposed.For the large number of wells adopting cable measuring and adjustment technology,the key is to realize the digitalization of downhole plug.For the key monitoring wells,cable-controlled communication technology needs to be improved,and downhole monitoring and data transmission technology based on composite coiled tubing needs to be developed to make the operation more convenient and reliable.For large-scale application in oil fields,downhole wireless communication technology should be developed to realize automation of measurement and adjustment.In line with ground mobile communication network,a digital communication network covering the control center,water distribution station and oil reservoir should be built quickly to provide technical support for the digitization of reservoir development.

A New Heat Transfer Model for Multi-Gradient Drilling with Hollow Sphere Injection

Multi-gradient drilling is a new offshore drilling method.The accurate calculation of the related wellbore temperature is of great significance for the prediction of the gas hydrate formation area and the precise control of the wellbore pressure.In this study,a new heat transfer model is proposed by which the variable mass flow is properly taken into account.Using this model,the effects of the main factors influencing the wellbore temperature are analyzed.The results indicate that at the position where the separation injection device is installed,the temperature increase of the fluid in the drill pipe is mitigated due to the inflow/outflow of hollow spheres,and the temperature drop of the fluid in the annulus also decreases.In addition,a lower separation efficiency of the device,a shallower installation depth and a smaller circulating displacement tend to increase the temperature near the bottom of the annulus,thereby helping to reduce the hydrate generation area and playing a positive role in the prevention and control of hydrates in deepwater drilling.

Optimum development options and strategies for water injection development of carbonate reservoirs in the Middle East

Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection development options and strategies are presented. Hidden baffles and barriers exist in carbonate reservoirs in the Middle East, so the reservoirs could be divided into different separated development units based on the baffles and barriers characteristics. Flexible and diverse profile control techniques such as high angle wells and simple and applicative zonal water injection have been introduced to improve the control and development degree of reservoirs. Three principal water injection development methods suitable for different carbonate reservoirs in the Middle East are proposed, including the combination of crestal gas injection and peripheral water injection, bottom interval injection and top interval production(buoyancy underpinning), and "weak point and strong plane" area well pattern. Based on the characteristics of very low shale content, fast and far pressure transmission in the Middle East carbonate reservoirs, a large well-spacing flood pattern is recommended, and reasonable development strategies have been made such as moderate water injection rate and maintaining reasonable production pressure drawdown and voidage replacement ratio, so as to maximize the recovery of reservoirs in the none or low water cut period.

Study on Water Injection Formula by Grey Correlation Method for Offshore Water Flooding Reservoir

Based on the development of the offshore water drive reservoir, the determination of reasonable water injection of monolayer and single well affects the distribution of remaining oil and development effect of oil field water flooding, so this paper, using the grey correlation analysis method, studies the main factors influencing the dividing coefficient of water-injection and weight. This method takes into account the effective thickness, permeability, injection-production well spacing, the number of injection-production wells, and the direction of formation coefficient factors such as the influence of the dividing coefficient for injection. The formula for water-injection multi-factor controlled is established, at the same time, applying water injection formula of this article and the conventional on injection allocation of A-platform offshore injection wells. And the difference of single-well injection-allocation quantity in layers is analyzed. Based on a platform offshore, layers exist in the process of water flooding and the problems such as the contradiction between the layers, put forward the necessity of layered water injection through this article to determine water injection formula and injection allocation on a platform of injection wells by implementing effect which can be found. A platform for water flooding development of water cut under control, natural decline rate reduced to verify the reliability and practicability of the formula to determine injection in this paper. It has certain guiding significance to the offshore for the water-injection development oilfield.

Research on performance testing of radio fuse based on virtual separation technology

The conception of virtual separation technology about high low frequency of electronic module was put forward based on the analysis of tactical performance testing of radio fuse.By means of the principle of fuse Doppler signal acquisition and injection,the high low frequency of electronic module was virtually separated,and one of important parameters—burst height of radio fuse is tested precisely.

CO_(2)分注井气嘴节流特性及矿场应用

为了解决CO_(2)分注井节流压差建立困难,气嘴易冲蚀的技术难题,通过构建CO_(2)物性变化的流动-传热耦合模型,揭示2级和3级节流气嘴的流场演化机制,优化设计气嘴结构、建立了绕流气嘴节流图版并开展现场应用。结果表明:流量为10 m3/d时,2级嘴径1.4 mm和3级嘴径1.6 mm的绕流气嘴分别能产生将近6 MPa和8 MPa的节流压差,证明绕流气嘴结构合理、性能可靠、能够达到调整层间压差的技术要求;参照气嘴图版优选的节流气嘴,现场应用20口井,节流压差可达4 MPa左右,调整后注入压力上升2.4 MPa,加强层相对吸气比例由9.7%上升至50.7%,有效调整了层间差异,解决了分注井小层吸气不均的问题。研究结果指导现场测调,为CO_(2)分注规模化应用提供技术支撑。

榆树林油田CCUS采油工程方案优化设计与实践

大庆榆树林油田扶杨油层属低孔、特低渗透储层,针对以往开发过程中存在注水困难、压裂有效期短、水驱开发难以有效动用的问题,开展CO_(2)驱油技术现场试验。从经济性、技术适应性、配套工艺成熟性等角度对采油工程方案进行综合评价,优选出单、双管分层注入工艺、高气液比举升工艺、注采两端个性化防腐工艺及物理化学组合解冻堵工艺等CCUS采油工程技术。结果表明:试验区投产初期及目前生产情况均达到了油藏预测指标;采出井平均泵效及检泵周期与外围油田平均水平相持平,注气井与采出井腐蚀速率小于行业指标;实现CO_(2)有效埋存108.9×10^(4) t,比水驱预测采出程度提高采收率4.39百分点,取得较好的驱油开发效果。研究成果为CCUS示范区的高效建设提供了技术支撑,开辟了大庆油田外围难采储量有效动用的新途径。

大型注水管网最优运行模式判别规则及参数优选方法研究

注水管网的能耗是整个注水系统的能耗中有一个重要因素,体现在管网选用的运行模式以及参数优化2个方面。通过对大量注水数据的计算与评价,发现运行模式的选择与整个注水系统中各单井的压力分布特征有密切关系,据此形成了注水系统最优运行模式的五条判别规则。根据这些规则可以确定注水系统最优运行模式的选择方法和寻优计算步骤,并给出了不同模式的数学模型及运行参数的优选方法。在此基础上开发了注水系统最优运行模式智能判别软件,软件可以根据需要修改其运行参数,变换运行模式,便捷地模拟运行各种模式状态下的能耗情况,以寻找注水管网最优运行方案。最后通过一个计算实例演示如何通过改变运行模式和参数得到了一个能耗较低的方案。此结果表明本方法可以作为大型注水管网选择最优运行模式与参数优化的有效手段。

井下旋流分离管柱的振动特性研究

为研究旋流分离管柱在注入泵和采出泵两螺杆泵抽吸条件下的振动特性,对其进行模态分析和瞬态动力响应分析。结果表明,不同工况下,旋流分离管柱的固有频率有所不同;固定注入泵一端和固定采出泵一端相比,固定采出泵一端各阶固有频率较小;螺杆泵转动引起的激振力和内部流量变化都会导致管柱变形,其中螺杆泵转动对旋流分离管柱变形影响较大;相对于固定采出泵,固定注入泵条件下旋流分离管柱产生的振动位移更大,是旋流分离管柱自身结构和注入泵转速产生更大激振力综合作用导致的结果;控制两个螺杆泵工作状态的时间差,理想情况下可以控制旋流分离管柱的总变形。

同心分注井在线电动验封仪研制及应用

随着油田开发的不断深入,分层注水仍是补充地层能量、实现油田稳产、提高采收率的主要开发方式,原有同心分层注水井验封技术存在仪器定位难、密封件易损坏、验封效率低等问题,采用设计和试验相结合的研究方法,研制了同心分注井在线电动验封仪,并配套测调、验封一体多功能地面控制系统,集成流量、上/下压力等多参数测试技术,实现了一次下井、多层验封测试。试验表明,验封仪的坐卡/解卡性能、胶筒坐封/解封性能、整机承压能力、密封承压能力均能达到要求,现场应用效果良好,有效解决了验封效率不高等问题,提高了分层注水测试效率和合格率,为提升油田精细注水效果提供了可靠的工艺技术。

AGM隔板的装配压力对阀控式铅酸蓄电池性能的影响

研究了AGM隔板的注液量、注液种类、纤维直径、增强隔板以及初始压力等因素对装配压力的影响。实验证明,注液量为饱和吸液量的90%,装配压力控制在60 kPa左右,可以明显改善阀控式铅酸蓄电池的循环寿命。

一种优化高频注入法PMSM无位置传感器控制

传统高频信号注入法采用带通滤波器分离信号,龙伯格观测器利用所得信号计算出转子位置,考虑到带通滤波器设计复杂且使高频信号幅值产生衰减,同时龙伯格观测器需要电机转矩反馈、转动惯量等多种机械参数,这些因素干扰电机控制系统的动态性能等。采用基于低通滤波器的信号分离方法可在不损失高频信号得到含转子位置信号;利用电机的转速、转子位置角以及其角加速度之间关系构建扩张状态观测器,可以避免测量负载转矩和对不确定扰动的估计。仿真及实验结果表明,该优化策略能够使电机在低速控制时稳定运行,且具有更好的低速动态性能。

基于响应面法的井下油水分离微型旋流器结构参数优化

针对微型旋流器分离性能受结构参数影响较大的问题,基于数值模拟方法和Box-Behnken设计,采用二阶多项式基函数构建微型旋流器底流口直径等5个主要结构参数与分离效率及压力损失间的数学关系模型,并对优化前、后的微型旋流器开展数值模拟和室内试验。通过对模拟数据进行方差分析验证了数学关系模型的精度,等高线图明确了结构参数之间的交互作用以及对分离效率及压力损失的影响程度。结果表明,底流口直径、小锥角、溢流口直径是影响微型旋流器分离效率和压力损失的重要结构因素;优化后的微型旋流器的结构参数为L_(1)=9.554 mm,D_(d)=2.184 mm,D_(o)=2.977,θ=9.39°,θ_(2)=2°,相较于初始结构分离效率提高了3.7%。研究结果可为高性能井下油水分离微型旋流器的设计提供参考。

采用非共沸制冷剂的双喷气增焓两级压缩热泵循环研究

提出一种采用非共沸制冷剂的双喷气增焓两级压缩热泵循环(DVIC),该循环在普通喷气增焓循环(VIC)的基础上采用分液冷凝技术,并增加一组闪蒸器,减少系统不可逆损失,改善热力性能。采用R290/R1336mzz(Z)非共沸制冷剂,对DVIC进行研究,并与VIC进行比较。结果表明:在设定工况下,DVIC比VIC拥有更优的循环性能,系统COP和(火用)效率分别提高5.82%和8.41%,压缩机功耗降低6.39%;在较低蒸发温度或较高冷凝温度的运行工况下,DVIC性能的改善效果更加明显。

井下油水分离装置现状与展望

油田进入开发中后期,采出液含水率急剧上升,如何降低含水率并提高采收率是开发后期需要解决的首要问题。井下油水分离技术利用水力旋流技术、重力分离技术或其他油水分离工艺实现在井下对采出液进行预分离,从而采出较低含水率的油水混合液,此项技术对于高含水油田具有很大应用前景。通过对井下油水分离装置的研究现状进行简要分析与总结,并指出目前井下油水分离装置存在的问题与挑战,同时做出展望,为其发展提供一定的参考。

旋流式井下二次油水分离同井注采技术适用性分析

针对含水率已达99%、超过经济开采极限的采油井,为进一步降低地面产出液量,在旋流式井下一次油水分离同井注采技术基础上,通过采用井下水力旋流器串联的方式,将采出液在井下再浓缩,形成旋流式井下二次油水分离同井注采技术。室内实验表明,两个水力旋流器串联后,分流比在15%~45%时,最大分离效率达到98.5%。通过现场试验,验证了旋流式井下二次油水分离同井注采技术的可行性,可将地面日产液量降幅提高至85%以上,实现了因特高含水关停的井组再利用,提高了油井采收率,为特高含水油田后期经济、有效开发探索一种新的模式。

渤海油田高效投捞无缆分注工艺研究及应用

针对无缆智能注水技术应用于油田开发中,其工艺存在无缆智能工作筒电路可靠性不足、电池寿命短造成无缆注水管柱寿命低的问题,提出了高效投捞无缆分注工艺。研发的井下可投捞无缆分注工作筒将无缆注水工作筒的电子元器件、传感器部件集成在可投捞注水芯子内部,利用钢丝作业实现芯子的快速维修、更换,有效地延长管柱寿命。同时研发了配套的地面发码系统与高效压力波控制编码技术,通过软件和硬件的配合,实现了水嘴开度调节、流量预设等7大功能,有效地提高了无缆调节效率。目前渤海油田现场应用62井次,投捞成功率达到100%,注水合格率达到97%以上。该技术的研发可为海上油田的高效智能注采提供新的选择。

海上油田分层防砂分层注聚技术工艺优化

针对胜利油田已有的双管分层防砂分层注聚技术无法满足其海上低剪切、防堵塞、长效注聚需求的现状,对注聚筛管、环空安全阀及液控封隔器等核心工具进行了优化改进,形成了双管宽流道分层防砂分层注聚技术。优化研究结果表明:形成的注聚筛管采用倒梯形缝状结构,表面双疏涂层,自洁不堵塞,流通量提高25%~40%;优化环空安全阀过流通道使内外管环空过流面积增加3.3倍;优化液控封隔器结构,使胶筒肩部受力减小12.6%,坐封活塞面积增加0.78倍,解封后环空面积增大1.5倍。该技术已在海上油田成功应用35井次,井筒黏度保留率达93%,提高5%,平均注入压力下降1.1 MPa。该技术对油田海上、陆地化学驱区块的长效注采开发具有一定的示范指导作用。

Influence of Endwall Air Injection with Discrete Holes on Corner Separation of a Compressor Cascade

The aim of this study is to reveal the influence mechanism of endwall air injection with distributed holes on the corner separation of a highly loaded compressor cascade,so as to promote the application of injection in aero-engines.Single-hole and double-hole endwall injection schemes featuring different axial locations,pitchwise locations,injection mass rates and injection directions,were designed and investigated.Results showed that the corner separation was eliminated by endwall injection;the optimal single-hole injection scheme achieved an endwall loss coefficient reduction of 29.7%,with injection coefficient as low as 0.48%.The optimal axial location of single-hole endwall injection was at 82%axial chord,being the center of corner separation.However,as injection hole was located at upstream of it,endwall injection resulted in severer corner separation.The mid-span flow field was deteriorated after endwall injection,which was due to 3D flow effects,i.e.,AVDR(axial velocity density ratio)effect and low-momentum fluid spanwise migration effect.The optimal injection was achieved at low injection angle and from close to the suction surface on pitchwise.Double-hole injection exhibited inferior performance compared with single-hole,which was due to the interaction of the two injection streams and mixing of injection streams with the bulk stream.

海上油田电液联控单管分层注聚技术研究

针对传统单管细分注聚技术存在因聚合物吸附等造成测调仪投捞不到位、配聚器调配困难及有效期短等问题,研发了一种电液联控单管分层注聚技术。该技术包含电液复合分控装置、液控多级配聚器、非接触式热传导流量计等核心工具。电液复合分控装置通过1根主控电缆,实现1根液控管路分控多个液控工具,大大简化了井筒管线数量;液控多级配聚器解决了注聚过程中流量调节困难的问题,实现变排量调节和大压差注入;非接触式热传导流量计实现聚合物流量井下长效在线监测。目前该技术已成功应用3井次,分注层数2~3层,最大单层配注量130 m^(3)/d,测调次数达21次,测试准确率达85%以上,在井时间约600 d依然有效。该技术满足了海上油田“保黏、细分、长效”的注聚需求,具有较高的推广应用价值。