高强度堵剂优化及其在高含水油藏靶向调堵中的应用

针对河南油田高渗高凝特高含水砂岩油藏,对双激发无机堵剂的配方优化、耐温耐盐性能、封堵性能、耐冲刷性能、粒径匹配等多方面进行系统研究。结果表明,缓凝剂和离子平衡剂是控制体系凝固时间的主导因素,随着主剂与激发剂浓度以及温度的增加,双激发无机堵剂固结速度增大。配液水中矿化度较高时,硫酸根和氯盐会加快体系固结时间。双激发无机堵剂封堵能力强,耐冲刷能力和深部液流转向效果较好,可对高渗透层大孔道有效封堵,提高低渗岩芯分流率,其封堵率高于98.5%。现场应用效果证实,双激发无机堵剂能够实现深部靶向封堵,具有强度高、有效期长、成本低等优点,调堵后含水率大幅下降。

杏北开发区葡Ⅰ1~3聚驱注入界限实验研究

特高含水期油田注聚合物能够有效封堵大孔道,改变液流方向,提高波及体积,从而提高采收率。针对杏北开发区葡Ⅰ1~3主力非均性储层聚驱注入界限识别不清、注入参数选取缺乏依据的问题,基于不同储层渗透率、聚合物相对分子质量和聚合物质量浓度开展注入性实验,评价了注聚效果,确定了注聚界限。结果表明:聚合物相对分子质量越大、质量浓度越大,注入速度越低;注入速度高于0.35 m·d^(-1)为注入能力强,0.35~0.25 m·d^(-1)为注入能力中等,0.25~0.15 m·d^(-1)为注入能力较差,小于0.15 m·d^(-1)为注入能力差。

Variability in Quantity and Salinity of Produced Water from an Oil Production in South Kuwait

Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.

特高含水油藏剩余油分布特征与提高采收率新技术

渤海湾盆地胜利油区经过60多年开发,整装、断块油藏已处于特高含水开发阶段,含水率超过90%,稠油油藏进入高轮次吞吐开发阶段,整体采出程度不到40%,仍有大幅度提高采收率的潜力,需要攻关进一步提高采收率技术。针对整装油藏特高含水后期高耗水层带发育、低效水循环严重,断块油藏剩余油分布差异大、有效动用难度大,深层、薄层超稠油注汽难、热损失大,有碱复合驱油体系结垢严重,聚合物驱后油藏动态非均质性更强、剩余油更加分散以及特高含水后期套损井多、出砂加剧、精细分层注采要求高等难题,明确地质及剩余油分布特征,深化驱油机制认识,围绕整装油藏经济有效开发、断块油藏高效均衡开发、稠油油藏转方式开发、高温高盐油藏化学驱开发开展技术攻关,形成整装油藏精细流场调控技术、复杂断块油藏立体开发技术、稠油油藏热复合驱提高采收率技术、高温高盐油藏化学驱技术、特高含水期主导采油工程技术等特高含水油田提高采收率技术系列,开辟先导试验区,取得显著开发效果,实现工业化应用,支撑胜利油区持续稳产。

Full-vision maintenance in extra-high myopia from implantable collamer lens to trifocal intraocular lens implantation

Dear Editor,I am Dr.Ye Shen from the Department of Ophthalmology,the First Affiliated Hospital,College of Medicine,Zhejiang University,Hangzhou,China.I write to share my experience of full-vision maintenance in patient with extrahigh myopia from implantable collamer lens （ICL） to trifocal intraocular lens （IOL） implantation.

Impairment of extra-high frequency auditory thresholds in subjects with elevated levels of fasting blood glucose

This study was performed to assess whether there is an association between elevated Fasting Blood Glucose(FBG) and hearing impairment in Bangladeshi population. A total of 142 subjects(72 with elevated FBG; 70 control) were included in the study. The mean auditory thresholds of the control subjects at 1,4,8 and 12 kHz frequencies were 6.35 ± 0.35,10.07 ± 0.91,27.57 ± 1.82, 51.28 ± 3.01 dB SPL(decibel sound pressure level), respectively and that of the subjects with elevated FBG were 8.33 ± 0.66,14.37 ± 1.14, 38.96 土 2.23, and 71.11 ± 2.96 dB.respectively. The auditory thresholds of the subjects with elevated FBG were significantly(p < 0.05) higher than the control subjects at all the above frequencies, although hearing impairment was most evidently observed at an extra-high(12 kHz) frequency. Subjects with a long duration of diabetes(>10 years) showed significantly(p < 0.05) higher level of auditory thresholds at 8 and 12 kHz, but not at 1 and 4 kHz frequencies,compared to subjects with shorter duration of diabetes(≤10 years). In addition, based on the data of odds ratio, more acute impairment of hearing at the extra-high frequency was observed in diabetic subjects of both older(>40 years) and younger(<40 years) age groups compared to the respective controls. The binary logistic regression analysis showed a 5.79-fold increase in the odds of extra-high frequency hearing impairment in diabetic subjects after adjustment for age, gender and BMI. This study provides conclusive evidence that auditory threshold at an extra-high frequency could be a sensitive marker for hearing impairment in diabetic subjects.

Study of the Law about Water-Cut Variation for the Fractured Metamorphic Reservoir of Buried Hill with Bottom Water

Aiming at the complex flowing environment including the buried hill of Metamorphite, the active bottom water and the fracture at Budate Reservoir within Beir Depression of the Hailar Basin, combining the laboratory studies and based on analysis of its drive mechanism, field wells’ parameters were used to analyze the effects of different conditions of the fractured metamorphic reservoir with bottom water on its law of wa-ter-cut variation and the waterflooding efficiency. The results show that for the Budate buried hill reservoir with bottom water, the gravity should be taken into consideration to determine reasonable perforation ratio and production pressure difference. And because of the acid sensitivity of the buried hill reservoir, application of proper clay stabilizer will enhance the field oil recovery to a satisfactory extent.

基于卷积神经网络和迁移学习的特高含水油井生产预测

油井的实时生产监测对油田的辅助生产和精细化管理有重要意义。然而,针对仅有小样本生产数据、数据波动大且有缺失的特高含水期油井,传统的机器学习算法无法实现良好的生产预测。提出一种基于卷积神经网络和迁移学习的多任务生产预测方法。该方法不仅可以实现时间和空间上特征的自适应提取,还可以改善模型在小样本数据上的预测性能。结果表明:相比于基准模型,产液量和动液面的平均绝对误差分别降低31.26%和60.81%,决定系数分别提高1.89%和7.59%。基于迁移学习的MTCNN模型提高小样本数据油井的生产预测精度,实现了特高含水油井产液量和动液面的实时预测,对抽油机系统的效率优化、油井边缘设备智能化有参考意义。

Water-cut rising mechanism and optimized water injection technology for deepwater turbidite sandstone oilfield: A case study of AKPO Oilfield in Niger Delta Basin, West Africa

Through the analysis of the reservoir connection relationship and the water-cut rising rules after water breakthrough in the highly volatile oil AKPO oilfield, a new model of water-cut rising was established, and the timing and strategy of water injection were put forward. The water-cut rising shapes of producers after water breakthrough can be divided into three types, and their water-cut rising mechanism is mainly controlled by reservoir connectivity. For the producers which directly connect with injectors in the single-phase sand body of the single-phase channel or lobe with good reservoir connectivity, the water-cut rising curve is "sub-convex". For the producers which connect with injectors through sand bodies developed in multi-phases with good inner sand connectivity but poorer physical property and connectivity at the overlapping parts of sands, the response to water injection is slow and the water-cut rising curve is "sub-concave". For the producers which connect with injectors through multi-phase sand bodies with reservoir physical properties, connectivity in between the former two and characteristics of both direct connection and overlapping connection, the response to water injection is slightly slower and the water-cut rising curve is "sub-S". Based on ratio relationship of oil and water relative permeability, a new model of water cut rising was established. Through the fitting analysis of actual production data, the optimal timing and corresponding technology for water injection after water breakthrough were put forward. Composite channel and lobe reservoirs can adopt water injection strategies concentrating on improving the vertical sweep efficiency and areal sweep efficiency respectively. This technology has worked well in the AKPO oilfield and can guide the development of similar oilfields.

鄯善油田特高含水期CO_(2)吞吐增油与埋存试验

根据鄯善油田注CO_(2)吞吐井组先导试验,分析低渗透低黏度油田特高含水期开展CO_(2)驱油与埋存的注采特征及影响因素。结果表明,鄯善油田发育中—深层油藏,CO_(2)注入呈超临界状态,注入特征与注水类似,存在剖面动用不均和平面突进问题;CO_(2)吞吐生产具有“气态CO_(2)排出阶段、增油生产阶段、逐步失效阶段”的三段式开采特征;3口吞吐井换油率差异较大,增油效果主要受地下剩余油富集程度影响;CO_(2)主要埋存机理为溶解作用和矿化作用,同步埋存率高达95.6%。

强边底水海相砂岩油藏长期水驱开发机理及数模研究

南海东部海相砂岩油田生产实践表明,强水驱海相砂岩岩心的驱油效率远比传统实验岩心结果高,主要由于高倍水驱后岩石润湿性从亲水转变为强亲水,驱油效率也大幅提升,但相关认识难以应用于油藏数值模拟当中。通过CMG软件离子化学反应和相吸附方法,控制化学反应速率与水流速度成正相关关系,根据网格吸附离子浓度进行相渗插值,解决了油藏模拟中长期水驱后相渗时变问题。

特高含水油藏深部调剖技术界限研究

在分析特高含水油藏深部调剖效果变差原因的基础上，确定了影响深部调剖效果的地质因素和开发因素等技术指标，利用数值模拟方法建立了符合中、高渗透油藏地质特征的概念模型，并制订了特高含水油藏深部调剖技术界限图版。研究表明：原油黏度小于 5 mPa·s，渗透率级差小于 2 的油藏均不适合深部调剖；含水率为 90%～95%，封堵半径为 0.4～0.6 倍井距时调剖效果较好；含水率为 95%～98%，封堵半径为 0.6～0.8 倍井距时调剖效果较好。胜坨油田、温米油田和腰英台油田特高含水区块 48 个井组的调剖结果验证了深部调剖技术。

特高含水期水驱油效率计算新方法

特高含水期是油田开发的重要阶段,水驱油效率研究在该阶段具有十分重要的意义。水驱油效率计算是以油水相渗比与含水饱和度的关系为理论基础的,传统方法认为该关系呈线性,而矿场实践表明,这种关系仅适用于中—高含水阶段,在特高含水阶段则表现为非线性;因此,文中在深入研究相渗曲线特征的基础上,对油水相渗比与含水饱和度的关系表达式进行修正,并以修正公式为基础,重新推导出新的适用于特高含水期的驱油效率计算公式。实践证明,该公式符合特高含水期的开发规律,能满足油田实际生产的需要。

胜坨油田二区油井出砂规律及治理措施

为了有效治理胜坨油田二区油井出砂日趋严重的状况,对沉积环境、地层压力、采液强度、生产时间进行了统计分析,得出胜二区油井的出砂规律。在此基础上实施了提高地层压力和化学防砂挡砂工艺,使胜二区地层能量逐步上升,注采比达到0.97,采液强度下降3.3t/m。同时对各种稳定剂、抑砂剂的适应性进行了评价,使油井的平均含砂量下降0.2‰,有效延长了油井免修期,减少了出砂对油田开发的影响。

氮气泡沫驱提高高渗透特高含水油藏采收率技术——以梁家楼油田纯56块为例

梁家楼油田纯56块高含水、高采出程度,剩余油主要富集于构造顶部及厚油层上部,常规措施挖潜效果越来越差,剩余储量动用难度大,油藏处于低效开发状况,为此,开展了氮气泡沫驱提高采收率技术的研究。重建了该区的三维地质模型,利用数值模拟进行历史拟合和注入参数优化,预测氮气泡沫驱开发指标及经济效益,通过对氮气水、氮气泡沫同注或交替注入4类36个方案开发指标的分析对比,选择氮气泡沫同注,6口注入井分为3组交替注入2个周期,平均单井氮气注入量为73.6×104m3,起泡剂用量为75t,预计提高采收率5.7%。先导试验选取井组1注7采,6口井见效,综合含水率下降0.8%,增油量为8.1t/d,取得了较好的降水增油效果。

喇嘛甸油田特高含水期厚油层挖潜工艺

针对喇嘛甸油田特高含水期厚油层不同结构界面的情况和剩余油分布的类型，提出了3种厚油层精细挖潜的采油工艺：①长胶筒封隔器细分注水、堵水工艺，胶筒长1～3m，封卡薄隔层及附近的炮眼，封卡结构界面厚度为0．2m；②层内水力割缝射孔工艺，该工艺定位控制精度高，割缝无震动，对薄夹层及水泥环不产生损伤，试验的最小隔层厚度达到0．2m；③层内定位平衡压裂工艺，利用6种工艺管柱，可保护上、中、下结构界面及压裂层上、下结构界面，实施的结构界面厚度达到0．4m。这3种精细挖潜工艺均得到了应用，对特高含水期厚油层挖潜有较好效果。

中国陆相砂岩油田特高含水期开发现状及对策

在调研我国陆相砂岩油田开发现状的基础上,从中高渗透油田、低渗透油田及断块油田角度出发,总结并归纳不同类型油田面临的开发现状,制定有效开发战略对策.结果表明:中高渗透油田开发应立足于井网加密与三次采油相结合;低渗透油田应以CO2驱油,辅助微生物驱油的开发对策;断块油田应开展气驱、微生物驱和热采研究与试验的战略对策.该研究成果对中国陆相砂岩油田特高含水期的有效开发具有指导意义和借鉴价值.

特高含水期油田水驱规律特征研究

当油田进入特高含水期以后,在半对数坐标系下,油水相对渗透率比(Kro/Krw)与含水饱和度(Sw)的关系曲线直线段再次向下发生偏折,出现第二段直线段。在此基础上引进了二段直线法,即甲型水驱规律曲线在中高含水期及特高含水期各成直线段,可用于油藏开发预测和油田动态分析。通过对特高含水期采液指数、吸水指数和含水上升速度变化规律的研究,发现实际的采液、吸水指数和含水上升速度因结构调整的对策不同,变化规律不同,对特高含水期水驱油田开发具有一定的指导意义。

强非均质性油藏空气泡沫调驱先导试验——以胡状集油田胡12断块为例

强非均质性油藏注水开发后形成优势渗流通道,综合含水率高达98%以上。为提高该类油藏的采收率,在胡状集油田胡12断块开展了空气泡沫调驱先导试验。室内实验结果表明,空气泡沫体系不但能够与原油发生低温氧化反应,而且能够封堵优势渗流通道,提高最终采收率。现场实施空气泡沫调驱后,注入井注入压力提高了78%,5个月油井未见气体产出,水线推进速度大大减缓,试验井组的综合含水率下降了3.4%,产油量增加了38.5%。实践证实,在严重非均质性油藏特高含水开发期,空气泡沫调驱是封堵优势渗流通道、恢复地层能量、降低含水率和提高采收率的有效手段。

正韵律厚油层剩余油富集区水平井段优化研究

水平井技术是挖潜特高含水期正韵律厚油层顶部剩余油富集区最为有效的方法。在影响水平井开发效果的多种因素中,水平井段长度是水平井设计的重要参数,直接影响水平井的开发水平。本文以胜坨油田二区沙二段74小层为例,建立相似油田概念模型,利用精细油藏数值模拟,研究不同水平井段长度和无因次水平井段长度下的整个油藏水平井开发效果,研究成果为同类型油藏剩余油富集区的水平井挖潜提供了借鉴。