For high temperature and high salinity reservoirs, the foam formulation system is required to have better foaming capacity and foam stability under formation conditions in tertiary EOR. In order to obtain a new foam agent suitable for this type of oil reservoir, through the compounding and testing of 7 common oilfield foam chemical agents, 15 formulated foam agents are tested and screened. Then the foam displacement experiment of the dual sand packs model was established to simulate the new foam flooding process. The production dynamic of the high-permeability sand pack and the low-permeability sand pack was captured and analyzed, and EOR mechanism of the foam system in the heterogeneous reservoir was clarified. The experimental results show that the formulation of B4(anionic & nonionic combined surfactant) & FSN100(fluorinated surfactant) with a mass proportion of 2:3 (BF23) has the best performance in terms of foaming properties, low interfacial tension reduction, and oil washing efficiency. Furthermore, BF23 foam injection greatly increased the recovery factor from 36.7% to 61.6%, clearly displacing the remaining oil in the low-permeability pack. Finally, the new foam agent solution used in Shenger block of Shengli Oilfield shows its good value for enhanced oil recovery.

低渗小断块油藏资源丰富,然而低渗透油藏由于孔吼细小、渗透率低,常规注水开发不是行之有效的方法.注CO2可以大幅提高原油采收率,兼顾碳减排与提高采收率,是低渗透小断块改善开发效果的有效方式.胜利油田小断块、小砂体井网不完善,注CO2驱油难以实施,CO2吞吐技术通过注入-焖井-生产的方式开发,是一种井网不完善的小断块开发的有效方法.矿场实施CO2吞吐影响因素较多,需要进一步开展研究.本文通过数值模拟,研究了不同油藏条件下CO2吞吐效果,为矿场实施CO2吞吐提供指导.

There are abundant bottom water reservoirs in China. Unlike conventional oil reservoirs, bottom water reservoirs have various problems, such as early water breakthrough, short water-free oil recovery period, and rapid water cut increase. For example, during water flooding, the injected water easily breaks into the bottom water and does not effectively displace the upper crude oil. The recovery rate is generally low. Based on this phenomenon, an experimental study of nitrogen foam flooding in bottom water reservoirs is conducted in this paper. The seepage characteristics of nitrogen foam in oil and water layers are studied through one-dimensional core tube experiments. Through two-dimensional plate oil displacement experiments, we have revealed the fluid migration and distribution characteristics in the plane and vertical directions during nitrogen foam flooding in bottom water reservoirs; additionally, we have summarized the mechanisms of nitrogen foam in bottom water reservoirs involved in improving oil recovery characteristics. The research results show that the seepage resistance of foam in the water layer is much greater than that in the oil layer, effectively increasing the displacement strength of the oil layer. During the development stage of bottom water flooding in bottom water reservoirs, the water cut increases rapidly, the bottom water coning is obvious, and the residual oil is mainly distributed between the oil wells and the upper part of the oil layer near the wellbore. During nitrogen foam flooding, the foam enters the water layer to form an effective plug so that the subsequent foam is diverted into the oil layer; additionally, the oil is displaced laterally to the production well for production. When the foam enters the oil layer, it defoams and floats to form a secondary gas cap; this effect causes displacement of the residual oil at the top and effectively improves the displacement efficiency by weeping volume of the injected fluid”

为明确沾化凹陷孤北洼陷沙沙一二段储层平面展布规律,确定物源方向及沉积边界,利用岩心、录井、测井和地震等资料,对孤北洼陷沙一、二段的扇三角洲、近岸水下扇、砂质滩坝和生物灰岩滩坝等沉积体特征、平面展布及演化规律进行了系统分析.结果表明:沙二段低位体系域孤北洼陷湖水较浅,整体为滨浅湖相沉积.埕东断层下降盘以发育近岩水下扇为主,在桩34井区发育厚层生物灰岩.沙一段为湖侵体系域,湖广水深,主要在湖盆中心部位沉积泥岩和油泥岩,在中央隆起带、东次洼以及孤北南斜坡沉积薄层生物灰岩滩坝等湖相碳酸盐岩.随着湖水深度逐渐变深,碳酸盐岩滩坝越来越薄,并且有向东部迁移的趋势.该研究对提高研究区沉积相类型及展布规律识别的准确度、指导下步滚动勘探方向具有重要意义.

RTA (Rate Transient Analysis) is a valuable method for obtaining reservoir parameters and well performance, but current RTA models hardly consider the MLVF (Multi-Layer Vertical Fractured) well in a layered tight gas reservoir. To capture the production response caused by the fracture with non-uniform length and conductivity, a novel RTA model for an MLVF well in a layered tight reservoir was presented. In this paper, we present a novel tight gas reservoir RTA model, an extended MLVF well with non-uniform fracture length and conductivity to investigate the production decline feature by the combined RTA type curves. After that, the proposed RTA model is verified to ensure calculation accuracy. Sensitivity analysis is conducted on the crucial parameters, including the formation transmissibility, formation storability, fracture length, fracture conductivity, and fracture extension. Research results show that there are three rate decline stages caused by a multi fracture with non-uniform conductivity. The wellbore storage and formation skin can be ignored in the rate transient analysis work. The formation transmissibility affects the rate transient response more than the formation storability. The increase in fracture length, fracture conductivity, and the extension of a high conductivity fracture will improve the well's production rate in a tight gas reservoir's early production stage. Therefore, it is significant to incorporate how the effects of the MLVF well intercepting with non-uniform length fractures change conductivity. The RTA model proposed in this paper enables us to better evaluate well performance and capture the formation of complex fracture characteristics in a layered tight gas reservoir based on rate transient data.

桩海下古生界潜山受三期构造运动影响,断层复杂多样,沿断层发育多期裂缝,形成受断层控制的裂缝型储层.因此断层识别是研究碳酸盐岩潜山油藏储层分布规律的前提,受地震资料分辨率限制,相干、曲率识别断层技术难以适用于古潜山高陡断层识别.利用曲率蚂蚁体融合属性消除了地层倾角影响,清晰地反映了不同走向断层平面展布及纵向发育特征,极大提高了桩海地区下古生界潜山断层的识别效果,通过与常规地震解释对比,每平方千米可增加3～4条断层,有效指导了勘探开发部署.

通过构造特征、储层特征及油气分布特征的分析,总结了桩海地区下古生界潜山储集空间类型、有效储层发育控制因素、储层纵向发育规律及平面分布、试油试采、油藏类型等特征,指导了桩海地区下古生界潜山的勘探开发.

桩106块位于老河口油田的埕东凸起北部缓坡带上,整体地势较为平缓.前人研究成果表明,老河口油田馆陶组上段为陆相沉积,主要发育辫状河及曲流河等河流相沉积.根据研究区岩性、沉积构造、粒度及测井相等相标志资料,判断出研究区目的层段主要发育曲流河相;在前人地层精细划分和对比的基础上,以现代曲流河沉积模式为指导,以砂岩厚度等值线图为依托,测井相控制,地震资料约束,结合末期河道地震响应,完成曲流河砂体的精细刻画,在现有认识基础上,与动态资料充分结合,不断修正上述认识,最终构建曲流河砂体平面展布形态及剖面配置关系,识别曲流河单体主要构型要素为河道和末期河道,建立曲流河的末期河道组合模式.曲流河河道呈“串珠状”分布,为被末期河道分割的相互独立的砂体单元,末期河道的存在既细化了储层认识,又解决了油水矛盾.

构造控砂一直为断陷盆地分析调查工作的重点和难点.综合井-震、岩心和镜下鉴定资料,以渤海湾盆地济阳坳陷沾化凹陷东部始新统沙四上亚段—沙三段(SQ1-SQ3)为例,探讨构造主导下的控砂机制和沉积充填过程,取得认识如下:1)Ⅰ级构造转换带奠定盆地宏观构造-沉积格局,多阶构造坡折叠合湖平面升降控制三级层序内部体系域之间的砂体加积与沉积体系旋回性变化,Ⅱ级构造坡折和次级断层控制体系域内局部输砂系统和砂体展布,陡坡带往往不利于碎屑物质注入湖盆;2)SQ1-SQ2存在孤北和孤南两个独立输砂系统,SQ3两个输砂系统合二为一,SQ1主要发育进退积不明显的、小而多的扇三角洲,SQ2开始发育三角洲、(半)深湖和滑塌砂体,SQ3主要发育大型三角洲,(半)深湖区广泛发育滑塌砂体;3)构造活动通过构造转换带、坡折带、次级断层和陡坡带等主导多断湖盆控砂机制和沉积充填过程,气候仅可强化或弱化前者的控制作用,但不会改变盆地充填过程.

针对桩海潜山下古生界断裂复杂、剥蚀严重的海相碳酸盐岩地层对比困难的情况,充分利用测井、录井、地震结合,运用层序地层理论与基准面旋回分析方法,精细地层识别,指出了桩海潜山下古生界3个区域和局部不整合面在地震上的上超、削截、顶超、下超等反射特征,系统分析总结了桩海潜山下古生界各层系进一步精细层序对比划分的钻井、录井、测井以及沉积上表现特点,为进一步研究地层、储层空间展布规律奠定了基础.

本文应用精细油藏描述技术,对桩106单元隐蔽性疏松砂岩油藏进行地质再认识,引进边滩侧积体沉积理论,进行储集单元重组,根据重组结果,优化注采井网调整和设计,应用油藏工程理论,确定合理开发技术界限,保持了油藏的高效开发。

By analyzing the structural and sedimentary conditions of pool forming, the types of sedimentary facies of Es2 reservoirs in Wuhaozhuang Depression are studied, pool forming rules and distributional modes of Es2 subtle reservoirs are summarized. 3 exploration wells and 7 rolling development wells are deployed. It is found that in 3 oil-bearing fault blocks there are 203×104t of original oil in place being newly increased, which is the guidance for future exploration.