增产措施在靖边气田C区的应用效果分析

随着气田的逐步开发,地层压力逐渐降低,部分气井生产过程中井口压力已与集气系统压力持平,不能连续生产,并且在气田开发中后期,此类气井数量逐年递增。本文通过对几种增产措施应用的效果对比,得出其适用条件,为低压低产气井的开采提供依据。     

海上复杂断块凝析气田排水采气工艺技术探讨

消耗式开发的水驱凝析气藏,在开发中后期因地层压力下降,必然引起凝析油反凝析和边底水的侵入,地层中液相饱和度的增加,使储层中由单相流(气相)变成了多相流(油、气、水),极大地降低了含气饱和度和气相相对渗透率,从而导致气井产能急剧下降,造成携液能力降低而产生井筒积液,井筒积液又抑制气井的产气能力,导致气井停喷。要使气井恢复生产,必须排除井筒及地层中过多的积液,目前最有效的办法就是排水采气,通过对陆上复杂断块凝析气田成功的排采经验进行归纳总结,结合海上相似气田实际情况,进行了海上凝析气田排水采气工艺探讨,对于为海上凝析气田排水采气提供有益的参考。     

苏里格气田储层解水锁复产技术应用研究

苏里格气田开发中后期气井地层能量不断下降,部分老井存在井底积液引起近井储层水锁伤害,气井产量大幅下降,严重影响气田高效开发。通过分析储层孔隙水产出、水锁伤害机理,结合致密砂岩气藏储集特征,明确气井在生产过程中出现水锁伤害特征及气井动态响应特征,选取研究区块4口低产低效井开展储层解水锁工艺技术应用,现场应用表明,4口试验井实施解水锁工艺后单井日均增产气量5 573方、累计增产气量91万方,增产效果明显。     

气井管柱腐蚀机理研究及防治

文 2 3气田是一个整装块状砂岩气田 ,主块气井不产地层水 ,只含少量凝析水 ,投产 5年后陆续发现生产管柱大都腐蚀穿孔 ,严重的则断裂落井。研究发现腐蚀机理是天然气中CO2 气体与凝析水或地层水作用形成的碳酸水腐蚀。且腐蚀速度及腐蚀程度主要与气井产CO2 总量、CO2 分压、气流速度密切相关 ,气井应用加注缓蚀剂 ,应解决注药工艺及分散性问题。加强对 CO2 井内监测 ,及时进行工况诊断 ,定期检换生产管柱 ,改进油管节箍组装结构 ,优质防腐涂层是延长气井寿命的重要措施     

渤海某凝析气田高含水井复产分析及建议

针对渤海某凝析气田气井因高含水而停产的情况,基于对高含水井的产水氯根含量、邻井生产动态特征及储层裂缝等方面的研究,对气井的产水来源及水侵通道进行了分析,结果表明产出水为凝析水和地层水的混合水,地层水沿太古宇储层裂缝上侵,导致含水突升。根据气井的潜力分析、系统测试、关井前产量及邻井目前产量等方面的资料,提出了复产的措施建议及指标预测,为凝析气田后期的开发调整提供了一定的参考。     

泡沫排液技术在高含油积液气井的应用

随着衰竭式开发的加深,由于地层压力下降,举升能量降低,以致气井产量达不到临界携液流量,井筒积液严重。气井积液已经严重影响到气井的正常生产和气田产能发挥。泡沫排液采气技术具有施工容易、见效快、成本低等优点,对积液严重的凝析气井具有更重要的意义。本文结合两种新型适用于高含凝析油井(20%～90%)的泡排剂的现场应用,简述了该工艺的基本原理,分析了通过应用该工艺取得的经验和认识。     

三相流动凝析气井无阻流量影响因素分析

在凝析气藏开发中,单井的绝对无阻流量与合理产能是比较重要的参数,它直接影响到气井开发的可行性及整个气田的开发规模。本文在三相流动凝析气井无阻流量公式调研的基础上,针对凝析气藏开发中经常存在的反凝析及地层产水的现象,首先从理论上对影响凝析气井的产能因素进行了分析,确定了影响三相流动凝析气井产能的主要因素。     

MIT测井仪在牙哈凝析气田油套管质量监测中的应用

牙哈凝析气田是目茸我国已投入开发的最大的整装凝析气田,采用循环注气部分保持压力开采。投产6年来,凝析气井在高矿化度地层水和CO2的腐蚀下,油、套管均存在不同程度的腐蚀或穿孔。MIT测井仪是评价油、套管磨损的新型仪器,其测井数据可准确得出井下油、套管变形、穿孔及内壁腐蚀的情况,并使用MITpro、MITcal和NIITview程序直接观测井况,快速识别油、套管破损井段和情况,为以后的作业提供准确的数据,优化后续作业设计。     

凝析气井井筒结蜡的影响因素研究

在凝析气井的生产管理中,气井防蜡清蜡是其中一项重点工作。本文通过统计大涝坝气田和轮台S3气田各凝析气井井筒结蜡的不同情况,得出影响凝析气井井筒结蜡的不同因素:原油含蜡、压力、温度、产量、含水、气油比等,并通过对比分析,确定在影响凝析气井井筒结蜡的影响因素中,油压的影响因素占主导地位,为凝析气井的防蜡清蜡工作提供了依据。     

砂泥岩薄互储层地震预测技术在水平井设计中的应用

白庙气田位于东濮凹陷中东部,是中原油田探明储量规模最大的深层凝析气藏。该区气藏构造为多期断层发育的复杂断背斜构造,天然气分布主要受构造、岩性控制,含气跨度大,凝析油含量高,地露压差变化大,目前开发中气井普遍存在反凝析现象,地层、井筒积液严重。考虑到在相同产量条件下水平井产生的压降远低于直井,可以延缓反凝析过程,抑制反凝析堵塞,改变近井地层凝析油气的渗流模式,提出采用水平井开发。因此开展白庙气田储层预测,特别是主力砂体空间展布预测,优选储层分布稳定,剩余储量规模大的砂体,开展水平井提高产能先导试验。     

有效驱替理论在低渗透油藏中的应用分析

在低渗透油藏,注水井附近地层具有较高的注水压差,因而也具有较高的视渗透率。在生产井附近地层同样也具有较高的生产压差,和较高的视渗透率,可称为易流动半径。但是在低渗透储层中,易流动半径很小。而注采井问有很长的压力平缓段,压力梯度低,视渗透率也低,渗流能力很低,称为不易流动带,是影响低渗透油藏有效开发的主要因素。减小注采井距,在相同的压差下压力平缓段减小,压力梯度增大,视渗透率也有较大提高。在较高的压力梯度和较高视渗透率的双重作用下,渗流量会有较大的提高,水驱效果得到改善。为此,对低渗透油田适当减小注采井距,可以建立较大的驱替压力梯度和有效的驱油效果,能改善注水状况和采油状况,提高采油速度和最终采收率。     

DN—A、DN—B井生产阶段环空压力诊断分析

迪那气田属高温、超高压凝析气藏,在开发生产过程中,部分单井,如DN—A、DN—B井,典型地表现出生产套压和技术套压异常的现象,这严重影响着这些井的安全正常生产。当前国内外还没有形成一套针对高温高压气井环空压力诊断分析的方法。结合塔里木油田实际情况,首先分析压力来源并结合API—RP90标准计算各环空的最大许可工作压力;其次密切关注生产动态,及时发现生产出现异常的情况;三是现场通过环空放压手段,结合放出物质的各种性质分析井下管柱的完整性,同时排查井口设备安全隐患,最终得出气井套压出现异常的原因。     

子洲-米脂气田气井腐蚀因素及腐蚀规律研究

随着子洲-米脂气田的大规模开发,产水气井及产水量的逐年增多,因腐蚀而引起的管筒穿孔、断脱,井口及集输管网渗漏问题的日渐突显,给气田生产造成了严重危害和经济损失。为了准确掌握井下油套管腐蚀状况,需要系统分析影响井下管串腐蚀的主要因素、腐蚀程度及防腐效果及进行腐蚀规律研究。本文主要对子洲一米脂气田生产井的腐蚀性影响因素及腐蚀规律开展研究,通过整理检测气田整体区块的气质、水质和凝析油基础物性,结合对井筒的腐蚀挂片试验,通过应用腐蚀机理研究,分析判定了子洲-米脂气田天然气属于微含硫、低含CO2干气气藏,气井存在的腐蚀和结垢趋势,气田腐蚀主要表现为CO2腐蚀,对CO2分压、pH值、H2S、凝析油等主要因素和次要因素进行了系统分析,将来为下一步筛选合理缓蚀剂提供理论依据。     

Effect of Hydrocarbon and Non‐Hydrocarbon Gas Injection on the Interfacial Tension of a Gas Condensate System

Experimental results of interfacial tension (IFT) of condensate‐brine‐gas systems over a pressure range of 1000 to 8000 psi and a temperature range of 95 to 160 °C are presented. High‐pressure high‐temperature video‐enhanced pendent drop tensiometry was established to capture drop images for IFT measurements at various reservoir thermodynamic conditions. This paper serves as a building block to the essential practical understanding of the surface effects associated with improved condensate recovery from gas condensate reservoirs by gas injection. This understanding is critical for ascertaining gas injectivity, displacement and trapping in the pore spaces, and potential geological storage of CO₂.     

第一类水合物藏降压开采实验模拟

我国南海含下伏游离气的水合物储层具有实现下伏游离气和水合物分解气“两气合采”的地质条件,开采该类型水合物藏能够增加产气量,提高经济性。但目前该类型储层的开采模拟室内实验研究较少,开采规律认识不足。本文采用实验室自行搭建的三维水合物模拟装置,建立了一套含有游离气层的第一类水合物储层制备新方法,研究了水合物藏降压开采过程的产气产水特性。结果表明,采用甲烷水合物四相点以下的生产压力能有力地加快水合物分解进程,提高开采效率,当开采压力从2.95MPa降低到2.14MPa,快速产气阶段气体采收率增加10%,总开采时间缩短约38%,总采收率从73%提高到81%。当开采井井孔位于水合物层时,可能会在井孔附近出现水合物二次生成现象,从而导致开采产气速率显著降低,相比于开采井井孔位于气层,相同累积产气量的情况下生产时间延长30%左右。对比第一、三类水合物藏发现,第一类水合物藏的快速产气阶段持续20min以上,比第三类水合物藏延长一倍多,但总的气体采收率稍低。本文塑造的是气饱和的第一类水合物藏,对实际海洋水合物藏的模拟具有一定局限性,今后研究还需从实验装置尺度、分区控温方法、实验介质筛选、储层重塑稳定性等方面着手,解决储层重塑关键技术问题,为我国含下伏游离气的泥质粉砂型天然气水合物藏开采提供基础数据参考。     

分体式柱塞工艺在大牛地气田D1-74井的应用

大牛地气田随着生产时间的增加,气井压力逐渐下降,气井排液越来越困难,普通泡排工艺受泡沫密度、含有凝析油等因素影响,使得一些积液减产气井生产困难。针对以上原因,第一采气厂引进了分体式柱塞气举排水采气工艺,采气一队D1-74气井于2012年12月开始分体式柱塞工艺实验,通过实验已经取得了一些成果,有助于分体式柱塞工艺在大牛地气田的推广和应用。     

Investigation of well test behavior in gas condensate reservoir using single-phase pseudo-pressure function

Gas condensate reservoirs present complicated thermodynamic behavior when pressure falls below the dew point pressure, due to fluid dropout and change in the fluid composition. Condensate blockage in the near wellbore region reduces the well deliverability. Mixture composition change in the reservoir makes the interpretation of well tests in gas condensate reservoirs a serious challenge. In this study, at first the capillary number effect and Non-Darcy Flow on compositional simulation of gas condensate reservoirs were investigated and then well test analysis was carried out. The main objective of this work was to examine gas condensate well test analysis using single-phase gas pseudo-pressure and radial composite model assuming capillary number effect and Non-Darcy Flow. For this purpose some fluid samples were selected and results compared. Results indicate that estimation of reservoir properties below the dew point is in good agreement with actual input, particularly for lean fluid samples.     

The Effect of Fluoropolymer on Wettability Alteration of Sandstone at Elevated Temperatures

Gas condensate reservoirs are generally recovered using a pressure depletion drive. Gas can condensate into the liquid phase near the wellbore region when the reservoir pressure falls below the dew point pressure, which can kill gas deliverability. Wettability alteration is an effective means of overcoming this problem; core wettability can be altered from liquid-wet to gas-wet to alleviate the effect of condensate accumulation near the wellbore region. To establish the effect of fluoropolymer on wettability alteration in a gas-condensate reservoir, a gas-wetting alteration agent was synthesized by emulsion polymerization using different molar ratios of fluorine-containing monomers and acrylic monomers. FTIR and SEM were performed to analyze the structure of the gas-wetting agent. Contact angle measurements were used to assess surface alteration by the Owens two-liquid method. The effects of alteration agent concentration, salt concentration, pH and temperature on gas-wetting alteration were also evaluated. Results showed that the best molar ratio of fluoropolymer monomer to acrylic monomers was 1:2. The egg-like structure of the fluoropolymer latex on the core surface mainly contributes to gas-wetting alteration. The contact angles of brine and oil can be altered from 23° and 0° to 137° and 67° by 1 wt% FP-2 treatment, respectively. The surface free energy of the core was reduced from 67.52 to 1.66 mN/m. Moreover, the treated cores remain gas-wetting up to 100 g L^?1 of salt solution, 120 °C and within the pH range of 5–7. This novel gas-wetting alteration agent can be used to solve the problem of liquid blocking effects in gas condensate reservoirs and improve gas recovery significantly.     

封闭多井油藏中的压力恢复分析

A general method has been developed for analyzing pressure buildup data from a well located in a system with both production and injection wells in a closed, bounded two-phase flow reservoir. The proposed method enables one to calculate the total mobility or permeability-thickness product, the skin factor, the average drainage-area pressure and the injection-production ratio （at the instant of shut-in） with accuracy from pressure buildup （or falloff） data dominated by a linear trend of reservoir pressure. Out of thousands of well tests, several typical field examples have been presented to illustrate the application of the proposed method for analyzing pressure transient data from a well located in a water-injection multiwell reservoir. And the possible application of this method to heterogeneous systems such as naturally fractured reservoirs is also discussed. Approaches to aid practicing engineers in verifying the buildup interpretation （or recognizing the interference of offset wells） are presented. Extension of the presented method to a gas well located in a multiwell gas reservoir is also suggested     

气井凝胶堵水技术研究

气井产水是很普遍的生产现象,具有很大的危害。通过堵水处理能有效降低产水量,同时还能提高产气量,延长开发期,国外一些油田通过对气井堵水技术的研究,发展形成了一系列凝胶／气体注入技术应用于裂缝性气藏。进一步的成果是提高凝胶在基岩中的堵水效果。