To clarify the movement of the water flooding front in fluvial reservoirs, this research takes the BZ oilfield as an example. By considering the equivalent flow resistance theory for oil-water two-phase flow, the horizontal micro-element equivalent method and the strong heterogeneity of fluvial facies reservoir comprehensively, a calculation model for a non-piston water flooding front in a horizontal well pattern was established. First, five horizontal injection-production well groups in the BZ oilfield were taken as examples to calculate the water breakthrough time for the oil wells. The calculation results are in good agreement with the actual production performance. In detail, the advancing speed of the water flooding front in the high-permeability strip was 0.8-1.6 m/day, and the speed in the low-permeability strip was 0.12-0.35 m/day. When water is seen in the oil well, the advancing speed in the low-permeability strip is reduced, resulting in uneven displacement and the formation of non-dominant potential areas. In addition, the water flooding front advancing distance was simulated to be 300-450 m by establishing a reservoir numerical simulation model, which is close to the result of the proposed model, indicating that the calculation method is reliable. This research is of great significance for predicting the water breakthrough time of horizontal production wells, judging the weak affected area on the mainstream line, and optimizing water injection and tapping reservoir potential in good time.

Abstract With the rapid development of big data and intelligent algorithms, intelligent oil reservoirs production has emerged. It brings new ways to generate profits for oil fields. The key of this technology is related to the rapid processing of oilfield data, which enables to obtain production decisions faster. This article proposed a new method for intelligent production optimization of oil reservoirs based on big data. Firstly, according to the injection and production development data of the oilfield, a connection model between injection and production wells was established using the principle of material balance. This model not only helps to understand the corresponding relationship between injection and production data in the oilfield, but also enables to predict liquid production. Secondly, a new model was established through reservoir engineering methods which can predict the relationship between oil production and the injection multiples of pore volume, achieving the prediction of oil production in oil fields. Finally, in order to obtain the maximizing net present value, an optimization objective model was established successfully using intelligent algorithms. Compared with the numerical simulation method, this method saved a lot of times and costs. This method has been using on various types of numerical simulation conceptual models, and the calculation results are perfect consistent with the model results, with an error of only 5%. However, compared to the numerical simulation, it not only saves time and costs, but also improves oil production efficiency. This method was applied to a certain oilfield in Bohai and achieved excellent results. The results of research have strong promotion significance, which can be spread in more oil fields in Bohai.

渤中34-9油田是截至2022年渤海已发现受火成岩影响最大的新生界砂岩油藏,在我国海上油田开发中尚属首次,火成岩精细识别以及火成岩对砂岩储层侧向封堵性研究对于油田高效实施至关重要.文章充分利用岩心、微观薄片、钻测井及正演模拟资料,精细表征不同火成岩相,建立渤海地区不同火成岩相识别模板.从岩石学特征和测井物性表征等方面开展火成岩封堵性评价,明确研究区主要发育岩性—构造油藏,火成岩对含油圈闭以分割和封堵作用为主,并针对性开展火成岩对砂岩储层封堵性研究,总结火成岩侧向封堵砂岩圈闭模式,提出有利挖潜区.研究表明,研究区主要发育火山通道相、侵入相和溢流相火成岩,明确研究区岩墙侧向封堵、层状火成岩岩体侧向封堵和层状火成岩岩体侧向不封堵3种火成岩侧向封堵砂岩圈闭模式,其中前两种火成岩侧向封堵模式可作为良好的潜力评价区.油田78 口开发井的成功实施,丰富了渤海地区火成岩发育区砂岩油藏勘探开发的技术手段,对渤海乃至国内外类似油田的勘探开发经验具有重要的指导意义.

为准确反映储层内部非均质性,以指导油田后期开发调整,有必要对砂体开展流动单元研究.综合应用测井、地震、分析化验和动态资料,采用熵权Topsis法对渤海B油田开展浅水三角洲储层流动单元划分.研究表明,研究区浅水三角洲储层非均质性较强,孔隙度、渗透率、泥质含量和饱和度中值压力是影响储层储集渗流能力的主要因素,根据以上4类参数可将储层划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四类流动单元.流动单元的分布受到沉积相的控制,Ⅰ、Ⅱ类流动单元主要分布在分流河道和分流砂坝中,连通性较好;Ⅲ、Ⅳ类流动单元主要分布在分流河道边部和溢岸砂中,连通性较差.流动单元的组合样式对连通性具有明显控制作用,不同流动单元间形成渗流差异界面,使得砂体内部弱连通或不连通,导致剩余油大量富集.

Based on the comprehensive application of logging,analytical test,and dynamics in E 2 s 3M of Huanghekou Sag,according to the entropy principle,it is proposed a method of quantitative characterization of waterflooding heterogeneity using entropy weight.And then the controlling factors of water flooding heterogeneity and the distribution law of remaining oil are clarified.The results show that the inter-stratum heterogeneity is weak while the infra-stratum heterogeneity is strong,the stratigraphic coefficient,the permeability protrusion coefficient,and the distance from the fault are the main factors affecting the water flooding heterogeneity,while the porosity,permeability,and shale content are less affected.The water flooded formations can be quantitatively classified into four classes according to the water flooded index:unflooded（If w ≥0.80）,weakly waterflooded（0.74≤If w ＜0.80）,moderately waterflooded（0.65≤If w ＜0.74）and strongly waterflooded（If w ＜0.65）.The remaining oil in the study area shows two distribution styles,namely,marginal break-control type and isolated type,with marginal break-control type predominant.According to the research results of the study area,adjustment wells were deployed in the area with a high value of water flooding index located in the high part of the structure near the fault,and the actual production of this well is consistent with the research results of water flooding heterogeneity.The results of the study are useful for the research on water flooding heterogeneity and remaining oil prediction in similar oilfields.

Carbonate rock buried hill is one of the important oil-gas reservoirs in Bohai Sea. Taking Z Oilfield,the key development target in Bohai Sea area as an example, the characteristics, formation mechanism and geological development model of carbonate rock reservoir are comprehensively analyzed by using basic data such as drilling and logging,cores,microscopic thin sections and seismic data. The results show that the lithology of carbonate rock buried hill reservoir is mainly dolomite,with the reservoir spaces of intergranular pore,fracture and dissolution pore.Carbonate rock buried hill reservoir is mainly controlled by sedimentary,diagenetic and structural factors. Combined with the characteristics of single well and vertical karst zonation,the buried hill can be divided into surface weathering zone,vertical seepage zone and bedding dissolution zone. Under the influence of multiple factors such as diagenesis and structure,the reservoir in the upper oil formation is more developed than that in the lower,with full-region development for the former and limited development for the latter. The karst zoning and geological model of reservoir distribution provide the basis for next adjustment and potential tapping direction.

陆地定向井密井网开发模式在海上浅水三角洲油田适应性差,对海上浅水三角洲油田水平井开发技术开展研究.以浅水三角洲沉积模式为指导,根据地震沉积学原理,提出了BZ油田浅水三角洲储层的形成条件、成因机理及分布特征;结合大尺寸物模实验及油藏数值模拟方法对一次井网进行部署与优化.BZ油田浅水三角洲储层发育类型为多个单一分流河道侧向迁移叠置所形成的连片朵叶状复合砂体,识别了3种河道接触样式.海上浅水三角洲油田一次井网采用水平井交错井网,储层上部采油、下部注水开发效果最好,提出3种河道接触样式下井网优化方法.首次提出了海上浅水三角洲油田基于单河道的水平井单砂体布井开发技术,在BZ油田应用,开发效果评价为一类.

The Neogene fluvial reservoir in the Bohai oilfield is one of the leading development horizons for increasing reserves and production in the Bohai oilfield.However, the development of offshore fluvial reservoirs is faced with the problems of thin reservoir thickness, narrow plane width, rapid lateral change, and thin well pattern.Taking the KLA oilfield as an example, this paper discusses the nuanced characterization and configuration of a single channel controlled by sedimentary facies to guide developing offshore river facies' narrow channel main control oilfield.Firstly, based on a large number of core data, the acceptable sedimentary facies identification is realized, the sedimentary model of the study area is established, the delicate calibration of logging facies and seismic facies is realized under the constraint of the sedimentary model, and a set of technical methods for nuanced reservoir characterization guided by seismic sedimentology is summarized, to realize the boundary identification of composite channel configuration and further realize the nuanced characterization of the single narrow channel.Based on this set of technology, it guides the smooth implementation of horizontal wells in the oilfield.The drilling encounter rate of the reservoir in the horizontal section of the single well exceeds 90%, ensuring the injection production connectivity and increasing the reserve production rate by more than 10%.

In normal pressure of reservoir, formation pressure and depth can not fully reflect the linear relationship between the formation pressure with depth, the change rule of reservoir measured formation pressure and often reduced pressure, understanding unclear cause fluid properties. By introducing basic principles of hydrostatics. The relationship between pressure coefficient and mathematical depth is discussed by mathematical induction analysis of measured pressure data of nearly 50 normal pressure reservoirs in Bohai Oilfield. The results show that the reservoir pressure data is linearly distributed with depth, and the pressure coefficient is inversely proportional to depth. When the depth becomes shallower, the pressure coefficient increases and approaches the reservoir level. As the depth increases, the pressure coefficient decreases and approaches the hydrostatic pressure coefficient infinitely. The study can more accurately analyze the reservoir pressure changes, which is helpful to study the oil and water distribution, reservoir connectivity and fluid properties of atmospheric pressure reservoirs.

渤海A油田沙三中段为辫状河三角洲前缘沉积,单砂体厚度薄,储层横向变化快,为典型的薄互层储层.受限于地震资料垂向分辨率,薄互层储层平面展布难以预测.在海上油田开发过程中,为节约作业成本,开发井一般采用随钻测井,只能得到伽马、电阻率曲线,缺少声波和密度曲线.针对油田储层发育的特点以及开发井缺少声波曲线等现状,尝试开展基于精确模型的地震多属性分析技术预测薄互层的平面展布.首先利用泥质含量曲线和电阻率曲线,采用基于支持向量机预测声波、密度曲线,分别制作多口已钻开发井的精细合成地震记录.在合成地震记录集提取多种地震属性,与井点砂地比交会分析,得到对砂地比敏感的地震属性.并在实际地震资料提取敏感地震属性,成功预测渤海A油田沙三中段薄互层平面展布.以数据为驱动,赋予地震属性地质意义,探索了中深层薄互层储层的定量研究方法,对类似油田薄互层储层预测有一定的指导意义和借鉴作用.

渤海B油田明化镇组下段发育典型的浅水三角洲储层,浅水三角洲复合砂体为多期次单砂体切割叠置形成,内部非均质性强,同时海上油田稀井网大井距,也给深入分析储层内部结构带来了困难.为进一步提高砂体动用程度及开发效果,在储层地质学理论指导下,应用海上高分辨率地震资料、丰富的动静态数据,基于砂体的井震响应特征,对主力砂体开展精细解剖.总结了砂体成因类型及叠置关系,形成了井震约束下的单砂体构型解剖思路,明确了砂体构型边界及接触关系,提出了不同类型砂体构型解剖方法.在单砂体构型解剖的基础上,融合地震地质信息,建立三维构型模型.研究表明,井震约束下的砂体构型解剖及界面等效表征在渤海B油田的地质建模及油藏数值模拟中取得了较好的应用效果.

储层内部渗流屏障的分布特征与定量规模对油水运动规律与剩余油分布的控制作用,一直是油气田开发地质研究工作的核心.以渤中A油田为例,综合测井、岩心等资料,建立研究区6种岩性的识别图版,对研究区水平井进行岩性解释.结合储层精细解剖的成果,明确了废弃河道及分流砂坝坝缘这2种主要渗流屏障的分布模式及定量规模.废弃河道在平面上呈树杈状分布于分流砂坝之间,岩性主要为泥岩和粉砂质泥岩,平面宽度约5～25 m,延伸长度一般小于1 km,孔隙度约5％～15％,渗透率小于4×10-3μm2.分流砂坝坝缘沿砂坝四周发育,多为泥质粉砂岩和粉砂质泥岩互层,平面宽度约10～20 m,孔隙度约10％～20％,渗透率约0.10～0.30μm2.此外,落淤层通常披覆于分流砂坝内,发育密度受季节性水流影响,钻遇宽度一般小于5 m,垂向厚度一般小于1 m.

本文提出基于蜻蜓算法和最小二乘向量机的地震多属性储层预测模型,利用蜻蜓算法对最小二乘支持向量机的惩罚系数和核系数进行优化,从复地震道类、振幅统计类、频谱特征类和吸收衰减类中优选出12种地震属性作为输入变量,选取储层厚度作为输出变量.以渤海X油田为例开展了实证分析,预测结果与PSO-LSSVM、FOA-LSSVM模型预测结果进行对比分析.研究结果表明:基于蜻蜓算法和最小二乘向量机的地震多属性储层厚度预测模型计算精度高,对油田勘探开发具有一定指导意义.

断块油田内部低次级断层,由于规模小、区域地质特征、成藏条件存在差异性,应用Yielding的断层封闭性评价方法预测圈闭的油藏高度以及油水分布与实钻吻合度不高.为了提高预测精度,提出利用油田内部钻井、流体压力等资料,通过建立断块的深度压力模型,对断层泥岩比率ISGR与过断层压力差(Ap)进行拟合确定符合区域成藏特征的定量评价关系式,并根据拟合图上封闭失效区域识别断层封闭的ISGR参数下限,二者结合定量判断断层封闭能力的评价方法.运用该方法对K油田4井区的断块进行研究发现,4井区南块I油组与中块II油组上、下段为同一油水系统,研究结果得到油藏动态认识的支持.

渤海南部海域新近系明化镇组浅水三角洲储层呈朵叶状广泛分布,由于储层成因及结构复杂,常规的基于复合砂体储层表征精度较低,制约了油田开发中后期剩余油分布认识和挖潜.以渤海南部海域BZ28油田1167砂体为例,在浅水三角洲现代沉积演化模式指导下,综合应用高分辨率地震属性、测井相、水平井地质导向及生产动态等资料,由复合河道、分流砂坝、分流砂坝内部沉积朵体逐级次对砂体构型单元进行划分.研究表明:研究区浅水三角洲储层平面呈分流河道与分流砂坝相间沉积分布特征,其中,分流砂坝为储层沉积主体,由沉积朵体纵向叠加、低角度前积及溯流退积等方式拼接构成,分流河道为过水通道,储层厚度相对较薄.研究成果可有效指导在生产过程中对油层水淹特征的认识.

综合应用岩心、测井、地震和示踪剂等动静态资料,根据构型层次分析理论,对渤海湾盆地A油田复合分流砂坝进行了精细表征,阐明了其内部空间结构.研究表明:地震振幅属性指示储层的横向变化,而振幅变化率能够更好地反映单砂体接触位置,根据边缘检测理论,将两者结合能够良好地识别单一分流砂坝侧向边界;同时根据低角度前积抽象理论模型可以定量刻画每一期分流砂坝顺源边界.研究区单一成因分流砂坝长600～1 300m,宽400～800 m,厚2.5～7.0m;垂向上呈部分叠置、主体叠置和主体叠加3种接触样式,平面上呈孤立分布、边部侧向拼接和主体侧向拼接3种组合样式,总体呈“早期前积伴随侧向加积-晚期逐渐超覆加积”式演化.

轻质油藏注水井常存在井口压力不断升高的现象,酸化、微压裂等常规措施并不能有效降低井口压力.为进一步探究注入压力过高的原因,以流管模型为基础,依据水电相似原理,开展井间渗流阻力变化规律研究.结合达西定律推导了渗流阻力表达式:渗流阻力与储层形状和总流度有关.而非活塞驱替过程的总流度变化通常分为两种:单调增加(中、高黏),先减小后增加(低黏).原油黏度较小时,总流度会呈现减小的趋势,渗流阻力随之增加,导致注入压力升高,此时表现在注水井井口压力不断升高,即发生了"伪堵塞",严重制约油田注水.通过对渤海南部区域不同油田注采井间渗流阻力的计算,得到了能够反应渗流阻力变化规律的无因次阻力系数图版,图版展示了"伪堵塞"可能发生的含水阶段,能够有效指导注水井的治理.结合KL油田群的治理实践,当注水井发生"伪堵塞"时,可采取以下措施:(1)对高破裂压力、低裂缝发育的油藏,实施提压增注;(2)对低破裂压力、高断裂程度的油藏,采取层内生气调驱;(3)对超低原油黏度、埋藏深的油藏,可考虑气驱开发;(3)对多层合采开发油藏,应优先解决纵向水驱矛盾.

为明确渤海湾盆地莱州湾凹陷垦利L油田古近系沙三上段储层物性特征及影响因素,综合利用铸体薄片、扫描电镜、X衍射、孔渗测试、地层测试等多种分析测试手段,结合区域构造背景、沉积体系等相关研究成果,探讨了沙三上段储层物性控制因素,并在油田注水开发中开展了应用.研究结果表明:沙三上段储层平均孔隙度为28.9％,平均渗透率为762.7×10-3μm2,属于高孔高渗储层,储集空间以原生粒间孔为主,可见次生粒间孔和铸模孔,微裂缝发育;微裂缝平均宽度为180 μm,微裂缝的存在提供了高效渗流通道,使地层孔渗测试结果明显优于岩心测试数据;优质储层的分布主要受体系域、断裂活动和埋藏作用的影响,水进体系域厚层净砂岩是形成优质储层的物质基础,微裂缝发育提高了渗流能力,快速埋藏减缓了储层孔隙水的排出和储层物性的降低.根据优质储层发育特征及生产动态资料,优化水井分层配注,降低平面及纵向上水驱不均,实现了油田均衡驱替.

针对试井解释结果精度不高和多解性的问题,结合渤海南部河流相油田特点,以及生产井大多采用永久压力计生产的实际,在常规试井解释模型的基础上,基于空间拓展和时间推移尺度,提出四维试井分析技术.根据多层渗流理论、压力生产史或同井不同时期压力恢复资料,分别在空间上、时间上对试井模型进行约束.经对调整井D24井进行分析,试井解释四层段表皮系数分别为19.9、20.0、15.1和14.2,与实际地层严重污染相符,建议酸化作业后,该井日产油由30 m3提高至80 m3;应用该技术,定向生产井B27井前后进行了3次时间推移试井,通过调整井的实施,新增原油地质储量48.41×104 m3.该技术可有效判断井污染情况、储层边界情况和物性参数,有效指导油水井措施及井网调整.

黄河口凹陷渤中34地区明化镇组下段下部河控浅水三角洲前缘席状砂较发育.为进一步认识前缘席状砂体的发育规律,通过岩芯、钻井、生产动态、黏土矿物等分析对席状砂体沉积特征、控制因素及沉积模式进行综合研究.席状砂主要表现为薄层或薄互层特征,根据发育位置可以划分为水下分流河道边部及河道末端席状砂两种类型.基于高分辨率层序地层学原理,以基准面短期旋回为时间区间,将席状砂体的沉积模式划分为三种类型:湖水上升初期的河道弱席状化模式、湖水上升期至最大湖平面时期河道末端面状流增长模式以及最大湖平面时期席状化改造模式.随着基准面的下降,浅水三角洲前缘沉积类型亦从席状砂体向水下分流河道演化.暖湿气候、一定的水体规模及地形坡度条件是前缘席状砂体大面积分布的控制因素.研究成果为进一步加快明下段河控浅水三角洲前缘席状砂的勘探开发提供了依据.