Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

In order to recognize the distribution of dispersed remaining oil,reservoirs should be described in more detail and quantitatively to establish refined and sophisticated 3D quantified reservoir model which can reflect the detailed variation in the reservoir and its structure.The key point of sophistication and quantification of reservoir characterization is to describe the geo-metry of interwell sandbodies and to estimate their reservoir parameters.

Development of High Viscous Oil in Sandstone Reserviors During the High Water Cut Stage，Gudao Oilfield

The oi!bearing area of Gudao Oilfield covers 80.9 square kilometers.with 373 million tons of oil in place.It is a large drape anticlinal.Neogene Gu-dao Formation is main oil-beraing reservoir devel-oped with dip gentle from 30'to 1°30'in general.The main oil-bearing sequences can be divided into 6 sand groups and 34 layers in detail.in which the Ng°-Ng°sand groups are the main payzones in which oil in place accounts for 97.2%of the total.

Complicated water-oil distribution and water out in high permeable fracture and cave system,but relatively good oil-bearing condition presents in low permeable ones

According to drilling core analysis and a lot of.field information,it was proved that the current reservoir range above oil-water contact detected by observation wells,was no more a complete pure oil bearing zone with exception of water cone,but a complicated oil-water mixed zone.The oil,satura-tion in the fracture system varied greatly.The large fractures with width of over 100μm were al-most water flushed,the middle fractures between 50-100μm were water encroachment zone and the small fractures less than 50μm were still in a good oil-bearing condition.

Developing High Water-cut Oil Fields Deeply to Enhance Their Oil Recovery

As stated above,the ultimate recovery of conventional oil in our country is estimated to be 33.6%,i.e,about 66.4%of the oil reserves cannot be recovered by water injection and may only be targeted for tertiary oil recovery or for other ty pes.of new technologics.A screening of 82 major oifields developed by water injection and an analysis of their potential showed that application of tertiary recovery technique such as polymer flooding,surfactant flooding and gas miseible flooding will inerease the oil recovery by 12.4%.The total recoverable reserve increment cor-responds to 56%of the current remaining recover-able reserves.This means that the recoverable r'eserves in OUr country can increase by more than one half by a fully tapping of the potential.Therefore,the development of tertiary recovery technology will be an important strategic measure in China's petroleum industry.

Study on Flow Unit of Heavy Oil Bottom Water Reservoir with Over-Limited Thickness in Offshore Oilfield

The upper Ming section of L oilfield is a typical offshore heavy oil bottom-water reservoir with thick fluvial layers. All horizontal wells are developed by natural energy. Due to the few drilling holes and influence by the resolution of seismic data, it is difficult to describe reservoirs with thickness over 20 meters. In this paper, seismic resonance amplitude inversion technology is introduced to restore the real response of thick reservoirs and interbeds by drilling and drilling verification, and the geological bodies with different thickness are displayed by frequency division RGB three primary colors. Flow units of heavy oil reservoirs with bottom water are divided according to the three major factors of interlayer, lithologic internal boundary and water-oil thickness ratio which have the greatest influence on horizontal well development, thick sand bodies are divided into 10 different flow units in three levels, each unit is separated from each other, and the reservoir structure, water-cut characteristics and water-flooding characteristics are different. The reliability of the research is improved by using the dynamic data of horizontal wells and newly drilled passing wells, which provides a basis for tapping the potential of heavy oil reservoirs with bottom water.

Diagnostic Method and Adaptability Analysis of Multiple Water Breakthroughs in Horizontal Well in Combined Well Pattern

The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this type of well pattern, determining the horizontal well is affected by which injection wells, especially when the injecting water breaks through, accurately determining the direction of water inflow will provide an important basis for targeted water well measures. Based on the production performance data of horizontal wells, the semi logarithmic relationship curves of water-oil ratio, derivative water-oil ratio, and cumulative production were used for the first time to determine the breakthrough problem of water injection in the surrounding water injection wells of horizontal wells based on their response characteristics. The adaptability of this method under different influencing factors was analyzed. Introducing the parameter of cumulative production not only preserves the variation trend of the derivative of water-oil ratio with time, but also facilitates the processing of actual production data.

断溶体油藏追踪油水界面变化的新方法

在底水驱动型断溶体油藏中确定原始油水界面及追踪动态油水界面变化一直是制约剩余油预测的重要难题。此文聚焦油水界面的油藏本质,精细量化了储集体的孔隙体积,开发动态数据试井化处理计算水油体积比,动静结合等比例分配油水体积计算出原始油水界面。在油藏内部划分出油水界面,后期根据水驱动用过程评估曲线划分水驱阶段,追踪动态油水界面变化,避免陷入前期常规方法选取参数困难、计算误差大的困境。开发实践证实该方法得到的结果误差小,计算方便快捷,具有推广应用前景。

普通稠油非均相复合体系组分驱油贡献率

非均相复合体系能实现协同调驱,在稠油开发方面极具潜力,但各组分驱油贡献率不明确,给体系优化与选择带来盲目性。针对由部分水解聚丙烯酰胺、双效型表面活性剂和预交联凝胶颗粒(B-PPG)组成的非均相复合体系,在分析其界面与封堵性能和驱油特征的基础上,开展了聚合物、二元复合体系和非均相复合体系驱油实验;依据3类体系驱油的采收率增幅,归一化计算了不同水油黏度比下非均相复合体系组分驱油贡献率。结果表明,0.106~0.150 mm(150~100目)B-PPG膨胀后的粒径中值为800μm。该非均相复合体系与渗透率为1.1μm~2的填砂模型匹配,运移封堵阻力系数与残余阻力系数分别为420.5和203.0,更低渗透率(0.30μm~2)的填砂模型则难以进入。对于渗透率级差约为3.0的并联填砂模型,非均相复合体系具有较强的调驱能力,最高注入压力为0.42 MPa、低渗透模型分流率最高达到42.2%;而二元复合体系的最高注入压力仅为0.25 MPa、低渗透模型分流率仅为24.3%。当水油黏度比为0.05~0.46时,非均相复合体系中聚合物驱油贡献率(43.1%~84.1%)最高,表面活性剂(22.1%~7.6%)最低,B-PPG(34.8%~8.3%)介于两者之间。水油黏度比(≥0.46)较高时,表面活性剂和B-PPG驱油贡献率较小,聚合物或二元复合驱后非均相复合驱增油潜力有限;水油黏度比(≤0.2)较低时,表面活性剂和B-PPG驱油贡献率大,水驱或聚合物、二元复合驱后非均相复合驱增油潜力较大。

低油水比油基钻井液体系研究

现阶段国内大量应用的油基钻井液体系油水比居高不下,且由于部分处理剂性能欠佳导致在钻井液体系中用量过大,两者叠加为降低油基钻井液体系综合成本带来极大困难。为此,提出了低油水比油基钻井液体系设计思路,并以此为指导研选了油基钻井液体系关键处理剂,通过配伍性实验构建了低油水比油基钻井液体系配方,并开展了现场应用。以保障在良好的乳化稳定性、流变性和较强的随钻封堵性基础上有效降低油水比为整体思路,研制了多活性点新型乳化剂,增加了分子内活性吸附基团的数量,在低油水比的情况下表现出良好的乳化稳定性和流变性;优选了具有良好增黏提切效果且可降低滤失量的有机土、具有良好降滤失效果的降滤失剂、具有改善流变性且提高乳化稳定性的流型调节剂,以3种处理剂为核心构建了低油水比油基钻井液体系;该体系在70/30的油水比条件下老化前后破乳电压>1000 V,在60/40的油水比条件下老化前后破乳电压>500 V,动塑比均>0.40,具有良好的乳化稳定性和流变性;低油水比油基钻井液体系在12口页岩水平井开展了现场应用,钻井液体系性能稳定、井眼净化效果良好,且乳化稳定性可控,大幅节约了基础油的用量,显著降低了油基钻井液体系的成本。

断控型碳酸盐岩油藏动态储量计算方法

断控型碳酸盐岩油藏非均质性强,不同尺寸的孔、缝、洞交错发育,采用一般物质平衡方法计算的动态储量可能大于静态储量。在引入水油比的基础上,考虑孔缝洞介质不同时的岩石压缩系数,得到了适用于断控型油藏的综合压缩系数,并在此基础上建立了断溶体流动物质平衡新方程,通过数值模拟,验证了新方程的准确性与适用性。结果表明:新方程计算的动态储量与数值模拟得到的静态储量误差仅为0.1099%,验证了新方程准确可靠;哈拉哈塘地区多口井用新方程计算的动态储量与地质建模雕刻的静态储量相对误差为-4.82%~-0.15%,远远低于物质平衡方程计算的动态储量与静态储量的相对误差,新方程计算结果更接近实际情况,更适用于哈拉哈塘地区断控型碳酸盐岩油藏的储量计算。

低成本低油水比低土相油基钻井液技术研制与应用

油基钻井液的应用范围较广,为降低油基钻井液成本,通过优选低成本油类基础液,开展研发新型单剂高效乳化剂,降低油水比,降低有机土加量等研究,建立了新型低成本低油水比低土相油基钻井液配方,同时对其性能进行了室内评价。实验结果表明:该钻井液油水比在65∶35~85∶15范围可调,有机土加量小于等于2.0%,密度为1.4~2.2 g/cm^(3),抗温达200℃,破乳电压大于800 V,高温高压失水量小于3 mL,油基钻井液单方成本较3号白油配制的油基钻井液降低15%以上,适用于-25℃条件,可满足辽河油区冬季施工需求。在辽河油区页岩油、致密油地层进行了应用,现场应用结果表明,低成本低油水比低土相油基钻井液性能稳定,封堵防塌性能良好,乳化稳定性良好,耐低温效果好,单方成本明显降低。研究成果有利于油基钻井液应用规模的扩大,可满足非常规油气资源低成本、安全、高效开发的技术需求。

渤海油田疏松砂岩超低油水比钻井液技术研究

油基钻井液已成为钻页岩气井、高温深井、水平井、大斜度定向井和各种复杂地层的重要手段,降低油基乳化钻井液的油水比,是大幅降低油基钻井液配制成本,降低生物毒性及钻屑含油量的重要途径,室内开发了一套超低油水比油基钻井液体系,油水体积比在50∶50~90∶10可调,具有较好的乳化稳定性,破乳电压1 000 V以上,同时形成的乳液呈纳米级分布具有较低的滤失量和较好的页岩井壁稳定能力,可满足页岩气水平井和大位移井的作业要求。

电潜螺杆泵入口处气液比动态变化特性分析

随着油田开发的不断深入,螺杆泵采油技术得到进一步发展与完善,近年来,在高含气和稠油等非常规油气藏中也得到广泛应用,但由于游离气和溶解气的存在,气体进入泵内会影响螺杆泵的工作性能和使用寿命。针对这种情况,综合考虑油气水三相流体对螺杆泵运行工况的影响,结合钻井液密度、生产气油比、含水率和气体状态方程,建立了螺杆泵入口处的气液比计算模型,并以大港油田J36-6和J36-8油井的生产数据进行模拟分析。结果表明,在动液面高度一定的情况下,增加下泵深度有利于降低泵入口处的气液比,高密度、高含水和低生产气油比是保证泵入口气液比较低的关键。

水驱曲线标定技术可采储量的极限含水率

在动态法标定可采储量中,水驱曲线法是一种重要的方法。该方法是注水油藏不采取重大调整措施、不改变开发方式、水驱状况基本保持稳定时的向前预测,其将极限含水率标准定为0.98,缺乏科学依据。不同油藏的水驱规律存在很大差异,应在4种水驱特征曲线中选择最接近油藏实际的水驱规律,而不是以技术可采储量最低去选择,造成标定的技术可采储量可靠性不强。为此,将4种水驱特征曲线和产量递减法进行反演优选和联合消元,形成新的水(液)油比与递减产量关系式,不仅可以确定极限含水率,也实现了动态法标定技术可采储量结果的唯一性。

一种具有促渗透功能精华水的开发及应用研究

采用体外细胞及斑马鱼功效验证实验,研究一种具有7∶3水油比精华水的促渗透功能及功效。结果表明,精华水对细胞增殖有相关作用,能够降低ROS表达起到抗氧化的效果,12 h时透皮吸收效果较好,具有促渗透效果及抗皱和紧致功效,其开发及应用研究结果在市场中有良好前景。

加氢尾油裂解制乙烯的工艺条件优化

为寻找加氢尾油裂解制乙烯的最佳工艺条件,分别考察裂解温度、水油比及进料流速对乙烯收率的影响,结果发现最佳工艺条件:裂解温度为855℃、水油比为0.8、进料流速为194.00 g/h,在最佳工艺条件下乙烯收率可达25.48%。

探析渣油加氢装置油水乳化的原因及处理措施

针对某炼厂渣油加氢装置反应生成油出现油水乳化的问题,通过两个平行系列进行对比分析,导致油水乳化发生的因素有很多,一旦装置出现油水乳化,会对整个分馏系统造成比较大的波动,严重则会危及装置停工。本文分析了出现油水乳化的原因有原料油的种类及性质、催化剂的活性和运转时长、装置的设计缺陷、循环氢流量、掺渣比等,并给出装置出现乳化后的处理措施,及时进行调整,保证装置的平稳生产。

基于储层时变的水驱优势通道治理对策

海上某水驱油藏存在明显的水驱优势通道。水驱优势通道的形成,宏观上是流固耦合作用的结果,微观上主要表现为岩石骨架结构、孔喉半径及连通性等特征参数的变化。通过非线性拟合建立渗透率及相渗曲线端点与水驱通量的时变关系,并耦合到模型中,建立物性随时间变化的油藏物性时变模型。在此基础上,开展井间水驱优势通道治理对策研究,提出调剖段塞封堵优势通道、组合段塞深度调剖封堵多级优势通道、组合段塞深度调剖后有效接替驱替三种治理方式,并应用于矿场实践。结果表明,针对油通比低于0.001m-1的水驱优势通道区域,三项对策均可达到一定的治理效果。以调剖治理优势通道,建议首要封堵中部优势通道,并在保证经济性的条件下适当扩大封堵范围。针对不同级别优势通道的组合段塞深度调剖治理方式,相比单段塞调剖效果更优。治理优势通道后有效的接替驱替方式是发挥封窜潜力的关键,采用组合段塞深度调剖后转调驱,可达到相对最优的优势通道治理效果。

低温固结阻水砂的研制及在春光油田的应用

春光油田稀油油藏成岩强度低,隔层厚度薄、破坏压差小。油田目前综合含水超过80%,出细粉砂严重,机械防砂有效期短,挤压充填防砂诱发隔层破坏导致底水锥进,水淹油层,而化学固砂施工风险大,国内覆膜砂固结温度相对较高(不小于50℃),不能完全满足地层温度下固结防砂的需要。根据疏水材料接触界面憎水、聚合物分子膜溶胀等机理,研发了一种固结阻水砂,室内实验显示,阻水砂能在20~60℃的条件下48 h内固化,40~50℃的固结抗压强度超过6 MPa,50℃初始固结时间83 min,48 h达到8.25 MPa,固化强度和初始固结时间满足现场固结防砂需要。测试阻水砂固结体表面水相接触角为90.9°~105.2°,具有疏水性。岩心流动实验表明,阻水砂人工岩心驱水阻力大于驱油阻力,水油阻力比值大于1,表现出良好的阻水透油性能。现场试验施工2井次,油井恢复产状后,综合含水下降7%~12%,取得了明显的增油降水效果。

不同水油黏度比下乳化对稠油复合驱的影响

化学复合驱是稠油提高采收率的关键技术之一,当前复合体系研发中越发强调乳化降黏机理,形成了高效乳化体系,但是强乳化产生的驱油增量尚不清楚,难以判断乳化对驱油的实际贡献。利用性能显著不同的1#(超低界面张力复合体系)、2#(乳化复合体系)、3#(兼顾超低界面张力和乳化的双效复合体系)体系,开展了系列的界面张力、乳化性能和不同水油黏度比下的驱油对比研究。结果表明,2#乳化复合体系和3#双效复合体系较1#超低界面张力复合体系更能稳定稠油乳状液。乳化对稠油复合驱的贡献因水油黏度比的不同而存在差异:水油黏度比小于0.200时,3#双效复合体系较1#超低界面张力复合体系采收率增幅高3.6%~6.7%,乳化能够增强体系驱油能力;当水油黏度比大于等于0.200时,3种复合体系驱油效果相近,乳化的影响显著减小,甚至可以忽略。泡沫复合驱较二元复合驱采收率增幅显著提高,且其可将稠油驱替对复合体系乳化性能要求的水油黏度比界限从0.200减小到0.150。对于稠油复合驱,应依据水油黏度比的差异,确定对复合体系性能的要求。