风城油田重18井区浅层SAGD双水平井钻井技术

SAGD钻井技术是开发超稠油油藏的一种前沿技术,在国内外的超稠油油藏开发中已经被大规模采用。2008年新疆油田公司开辟先导试验区并尝试使用SAGD技术开采风城油田重18井区超稠油油藏,取得了一定的效益。在此基础上,近年来开始进行大规模的SAGD钻井。本文结合近年来施工的SAGD双水平井中其中的一对井——FHW117P生产水平井和FHW117I注汽水平井,对SAGD双水平井钻井技术进行了介绍。塔式满眼防斜钻具、磁性定位导向技术、针对性的钻井液技术等,是该对双水平井顺利完钻的关键。另外,通过保持钻井液良好的润滑性、使用可循环式加压装置和大质量钻铤对筛管施加下压力的措施,使Φ177.8 mm筛管顺利下入Φ215.9 mm井眼内。     

Novel insights on the impact of top water on Steam‐Assisted Gravity Drainage in a point bar reservoir

As efforts are made to efficiently exploit and recover bitumen resources in Canada, increasingly more complex reservoirs in the Athabasca area continue to challenge the application of Steam‐Assisted Gravity Drainage (SAGD) technology. Several studies have been done to investigate the impact of heterogeneities/complexities such as shale barriers, lean zones, and top and bottom water on the performance of the SAGD process. However, the literature is deficient for point bar deposits with top water zones, a common occurrence in oil sands systems. This study, by using thermal reservoir simulation, examines SAGD performance in a point bar deposit reservoir where an overlying top water and an inclined heterolithic strata (IHS) is present. The results show that where the top water is unconfined and steam injection pressure is higher than that of the top water zone, there is a loss of thermal energy, but the top water does not impact steam chamber development. At steam injection pressure lower than that of the top water zone, top water continuously drains into the reservoir and constrains the size of the chamber. However, the IHS zone helps to delay drainage of the top water into the chamber when steam is injected at underbalanced conditions. Finally, under proper steam injection pressure conditions, top water production can be considerably delayed.     

油砂油电加热开采技术应用

目前现有的油砂开采技术,无法开采地下100~250 m位置的油砂资源,本文介绍的ET-DSPTM电加热技术能有效解决此问题,并且工艺技术安全、环保、可靠。     

Sensitivity Analysis to Operational Parameters of the Offset Well During Fast-SAGD Process in Naturally Fractured Reservoir

Few studies were done to investigate performance of the Fast steam-assisted gravity damage (SAGD) recovery method especially in naturally fractured reservoirs (NFR). The authors studied some cyclic steam stimulated operational parameters effects on the Fast-SAGD performance in NFR. A synthetic 2D homogenous model was constructed by Computer Modelling Group's (CMG) and simulated using the STARS module. Comparison between SAGD and Fast-SAGD recovery methods in this model shows great increase in the oil production but small increase of thermal efficiency in the Fast-SAGD recovery method. Simulation outcomes represent 17% increment in ultimate recovery factor but small reduction in steam-oil ratio. Results show that increasing the number of offset cycles and injection period yield increment in the oil production. Increasing the offset injection rate causes growth in the oil production, but has an optimal value. By increasing the distance between the offset well and SAGD well pairs up to a certain value, oil production increases but decreases after that point. This is due to the ability of the fractures in making connection between the steam chambers in higher distances. When production bottom-hole pressure decreases, the heated oil in near well region is subjected to more pressure drop and causes more oil to be produced. More offset wells result in higher production but simultaneously lower recovery factors. Increasing and decreasing soak time as the last investigated parameter did not affect the trend of production anyway.     

非均质油藏双水平井SAGD三维物理模拟

为了改善双水平井SAGD开发过程受储层非均质性影响的问题,利用自主研发的双水平井双管柱结构三维比例物理模型和已有的注蒸汽三维模拟实验系统,研究了油藏非均质性对SAGD蒸汽腔展布的影响规律。研究结果表明：当储层存在平面非均质性时,双水平井SAGD在开发过程中存在蒸汽腔发育不均匀、水平段油藏动用程度较差等现象,影响了SAGD的开采效果;水平井采用双管柱结构可提高水平段油藏动用程度;合理的注采参数、有效的操作压力、较高的蒸汽干度以及稳定的生产井井底饱和温度与实际温度的差值控制均可有效改善开发效果。根据物理模拟实验的结果总结了双水平井SAGD生产各阶段的注采调控方法,将其应用于油田现场取得了较好的开发效果。     

超稠油油藏双水平SAGD 优化设计

曙一区杜84 块馆陶油层为一顶部和四周被水包围的特殊油藏, 为提高杜84 块馆陶超稠油油藏剩余油动用程度, 决定采用S AGD 开发技术。以油藏特点和开发现状为基础, 应用S TARTS 数值模拟软件, 采用变深度、不均匀网格进行油藏数值模拟, 对双水平井组合的SAGD 技术布井方式、水平段长度、水平段在油层中的位置、注采参数等进行了优化设计。实施效果表明, 各项参数的设计科学合理, 采用双水平井组合SAGD 技术, 提高超稠油原油采收率是经济可行的。     

双水平井SAGD预热阶段温度场计算

采用满足质量守恒的流函数方法,编制有限容积法程序,模拟计算了双水平井蒸汽辅助重力泄油(steam assisted gravity draining,SAGD)蒸汽循环启动预热阶段温度场演化情况。对比了纯导热与导热及热对流共同作用下所需预热时间的差别,给出了单位长度井散热速度和两井中间位置温度随时间的变化,同时,也分析了井间距对预热时间的影响。结果表明,单位井长度的散热速度随时间的延长逐渐减少,在初始阶段变化较快,然后以较慢的速度降低。这表明,以井筒恒热流边界条件的温度叠加原理分析方法,建立预测阶段温度分布模型,预测热联通需要的加热时间是不合适的。不同井间距工况预热阶段数值计算表明,影响预热时间的主要因素为两井间距,间距扩大一倍,需要的预热时间延长约为原来的4倍;原油黏度很大且随温度变化不太敏感或井间距较小的情况,自然对流换热作用很弱,在预测预热时间时可以按照纯导热模型处理,而相对不太黏稠的原油或井间距较大时热对流作用强,不能忽略对流传热的影响,自然对流换热可大大缩短预热时间。     

中深层超稠油SAGD开发动态调控技术

SAGD作为超稠油蒸汽吞吐开发的接替技术,2005年在曙一区杜84块馆陶油藏进行SAGD先导试验.实施过程中,先后遇到汽液界面不合理、水平段动用状况不均匀、水平井汽窜以及注采不均衡等问题.以SAGD操作理念为指导,以动态生产曲线为基础,以动态监测系统为手段,在借鉴国外成功经验的基础上,坚持自主创新,不断优化调整,研究出适合油藏特点的配套动态调控方法.综合利用阻汽控制、水平段均匀动用、水平井防窜以及注采平衡等调控技术.使先导试验操作平稳,达到或超过方案设计指标.     

直井与水平井组合的蒸汽辅助重力泄油产量预测

蒸汽辅助重力泄油（SAGD）是一种利用液体自身重力作为主要驱动力的热采方式。国外的SAGD先导实验，大多数是利用双水平井的组合方式进行，注入井和采出井都是水平井，而在辽河油田进行的先导实验，是利用直井作为注入井、水平井作为生产井的组合方式。针对辽河油田先导实验的注采方式，利用保角变换，将水平井转化为像平面上一口环形生产井的一部分；垂直注汽井变成像平面上的原点。对直井与水平井组合的SAGD井组，按照直井划定流动单元，分别计算叠加，可以得到水平井的产量，提供了直井和水平井组合的重力泄油产量预测方法。依据辽河油田杜84块SAGD先导实验区实际生产数据，利用文中提供的方法进行计算，预测的产量结果与油田实际数据非常吻合，证明文中推导的直井与水平井组合的SAGD预测方法是可靠的。