辽河油田超稠油油藏开采方式研究

辽河油田杜８４ 块兴隆台油层是一个超稠油油藏。由于地下原油粘度大,流动性差,因此常规直井蒸汽吞吐效果很差,平均周期油汽比只有０．３５。为了提高蒸汽吞吐开采效果,在油田现场采取了一系列技术措施,包括采用高效真空隔热油管、加深注汽管柱、采用大泵抽油等,措施后,周期油汽比提高到了０．５５９。同时,根据该油藏地质特征及原油性质,研究并试验了水平井注蒸汽开采、成对水平井蒸汽辅助重力泄油、水平裂缝辅助蒸汽驱及垂向燃烧辅助水平井重力泄油等新技术及开采方式。结果表明,水平井技术与重力泄油相结合,将是提高厚层超稠油开采效果的一种主要方式。     

SAGD 重油、油砂开采技术的创新进展及思考

蒸汽辅助重力驱油技术（SAGD）是目前重油、油砂开采中最常用的热采技术之一，相比传统注蒸汽、原位燃烧等技术具有置换稳定、地层接触面积大、驱油效果好、采收率高等优势，同时也存在成本高、蒸汽短循环等问题，为了更好地指导重油、油砂技术创新，开展了基于SAGD 技术的新进展研究。详细阐述了基于SAGD 的技术创新，即单井SAGD、膨胀溶剂SAGD、泡沫溶剂SAGD、燃烧辅助重力驱及氧添加蒸汽辅助重力驱等5 项新技术的原理、创新及优缺点。总结得出，创新一方面是体现在通过井型变化、蒸汽溶剂相结合扩大了蒸汽腔，提高了能量利用率和采收率，另一方面是通过注蒸汽与燃烧法相结合最大限度开采有效能源。基于SAGD 技术的创新发展为重油、油砂开发后续技术储备及创新提供了技术借鉴。     

稠油油藏水平井热采应用研究

本文油藏数值模拟技术研究了不同类型稠油油藏水平井注蒸汽开采的可行性、相应的开采方式及油层厚度与原油粘度对水平井注蒸汽开采效果的影响。     

Treatment and restoration of used Mineral-Oil-Based hydraulic fluids from different machines. Part 1: Dewatering,filtration and effect of viscosity modifier

In this work, characterization and treatment of used hydraulic oil samples were performed in three steps. In the first step, the physical and the chemical properties of fresh and used hydraulic mineral oil samples from various centrifugal casting and pipe drawing machines were investigated according to ASTM D 6158. Results show that water content, solid particles count and depletion of additives have considerably affected most of the oil properties. Used oil samples failed in the appearance, thermal stability, oxidation stability, foaming tendency, water content and particles count.

In the second step, a simple methodology for dewatering and filtration was adopted. This methodology involved settling, followed by dry-air bubbling for oil dehydration and finally vacuum filtration. Such process successfully removed considerable portion of solid particles and water in used oil samples. Appearance, pour point, water content, particles count, and acid number were restored to the allowable limits. While water separability, oxidation stability, thermal stability and foaming tendency still failed the limits after treatment. It is obvious that additives will be needed to restore the latter properties.

In the third step, viscosity modifier additive was added to the oil samples to enhance viscous properties. A linear increase in kinematic viscosity was witnessed at 100°C, while at 40°C, an initial linear increase at low viscosities was followed by lower slopes at higher viscosities.     

A new approach for optimizing productivity/injectivity in naturally fractured reservoirs based on fracture network detection using Fourier – wavelet transform analysis

Fracture detection is a key step for characterization and modeling of reservoirs for optimizing production by shooting to the casing right in fracture muster points. Actually, fractures play crucial role in production of oil and gas by introducing super conductive paths to the porous medium and the challenge is finding where they are.

Many approaches took advantage of sharp changes of rock physical properties in the presence of fractures for fracture detection. Likewise, wavelet transform analysis (WTA) is sensitive to changes in the inlet signal and can be employed for this purpose. Considering petrophysical data as input, fractures can be highlighted with change in near wellbore resistivity in the fairly fixed lithology. Decomposition of such signals after removing high frequency noises shows very valuable data hidden in the low frequency part of the original signal.

In this research, WTA is employed for finding fracture muster points in one of Middle Eastern carbonates. MSFL profile is de-noised and results show good match with interpreted FMI of under studied interval in highlighting open fractures. Application of this approach can help for finding hot spots for perforation or well path design of directional wells and also can eliminate running of image logs.     

Determination of asphaltene precipitation using a CPA equation of state

Asphaltene precipitation during natural depletion and miscible gas injection is a common problem in oilfields throughout the world. Therefore, predicting asphaltene phase behavior through thermodynamic modeling may help to control its precipitation and reduce the associated problems. In this work, a new modified CPA equation of state (EoS) was used to model asphaltene precipitation. This equation is based on a combination of a new physical part and the Wertheim association term.

The results of the new model were compared with the experimental data of five oil samples. The results showed that this modified CPA EoS can predict asphaltene precipitation with good accuracy.     

Evaluation of possible source rocks and extracts characteristics from Safir-1x well,North Western Desert,Egypt

The pyrolysis and vitrinite reflectance estimations for fifteen shale rock tests and additionally, geochemical burial history, and gas chromatography – mass spectrometry parameters were talked about to explore the hydrocarbon generation and maturation level and time, type of hydrocarbon produced of rock units of Safir-1x well. The results assign that the Bahariya Formation is poor to great source rock to create oil and gas, with a lower thermal maturation degree than the Khatatba and Alam El Bueib formation. Alam El Bueib is viewed as good to excellent source rock for oil and gas age, having marginally high level of thermal maturation at oil window at around 40 million years. Khatatba formation achieved the oil and gas generation window at about 80 and 50 million years separately and considered excellent source rock.

The molecular gas chromatography and mass spectrometry parameters demonstrated that the extracts of source rocks reflected that the Bahariya and Alam El Bueib extracts have a mixed sources formed under transitional conditions at low grad of thermal maturation. Khatatba source rock extracts originated from marine sources formed under reducing conditions at high grade of maturation.     

蒸汽辅助重力泄油技术在超稠油开发中的应用

对国外超稠油开发方式进行调研,利用数值模拟技术对辽河油区超稠油油藏进行了蒸汽辅助重力泄油(SAGD)开发可行性及油藏工程研究,确定了在杜84块馆陶组开展4个井组的直井与水平井组合SAGD试验。通过2a的现场应用,馆陶油层SAGD试验获得成功,目前处在蒸汽腔扩展阶段,井组日产油较蒸汽吞吐阶段上升了72t,预测SAGD开发可提高采收率27%。SAGD技术已成为超稠油油藏蒸汽吞吐后期的重要开发方式,可为类似油藏的开发提供依据。     

原油热裂解过程中的红外光谱演化特征及其主控因素

原油的红外光谱能够反映原油中各种分子基团的信息,对于简单、快速识别原油的成因类型和热演化程度有很大的应用潜力。通过对两个不同有机相来源的原油样品开展热解实验,初步研究了原油热解过程中红外光谱的演化特征及其主控因素。结果表明,随着原油热解程度的增加,不同类型原油的红外光谱具有相似的演化模式,可近似划分为两个阶段。在早期阶段(实验温度<370℃),热解油中甲基/亚甲基吸光度比值(A_CH3/A_CH2)变化不明显,而芳环分子基团吸光度(A_aro)及其与烷基分子基团吸光度比值(A_aro/A_sat)减小,这主要是由于原油中部分热稳定性低的化合物发生脱支链作用,形成了饱和烃组分,降低了芳烃/饱和烃比值。在晚期阶段(实验温度>370℃),热解油中A_CH3/A_CH2,A_aro和A_aro/A_sat     

SAGD井挤液扩容水力波及范围模型

风城油田陆相稠油油藏广泛采用蒸汽辅助重力泄油（SAGD）方式开采,由于储集层非均质性强、渗透率低,目前现场采用挤液扩容方式改造储集层,以缩短SAGD井预热周期。为了定量评价改造区域的形状,提出基于挤液扩容水力波及范围的可注性系数和挤液渗透率的概念和计算方法,推导了单口和两口水平井挤液扩容水力波及范围的解析解,最后应用模型对现场挤液施工的效果进行了预测,并结合有限元计算结果进行了检验。研究表明,所研究储集层的可注性系数为0.27~0.30,双井注水系统的水力波及半径和面积均随两井间距、水的有效渗透率、水平段长度和定排量施工条件下的注入压力增加而增加,随注入液黏度增加而减小。现场SAGD井挤液施工过程中需要尽量降低注入液黏度,在稳定排量的同时,逐步增加注入压力和近井地带的储集层渗透率,以优化挤液扩容效果。     

THAI技术开发厚层稠油油藏井网参数优选

厚层稠油油藏原油黏度高、埋藏深、油藏流体流动性差、动用程度低,采用THAI(从端部到跟部注空气)技术可提高该类油藏的采收率。通过数值模拟对排状布井方式的井网参数进行优选,得出影响因素的敏感性强弱依次为生产井水平段长度、注气量、井距、注气井到生产井水平段端部的距离。在此基础上,进一步分析厚层稠油油藏中不同布井方式的开发效果。结果表明:随着燃烧前缘向前推进,生产井中会产生气窜通道;方案2VIHP的采油速度和采收率优于其他方案;层厚是影响热量传递的重要因素;垂直注气井的开采效果优于水平注气井。     

Determination of asphaltene precipitation using a new CPA-based equation of state

Asphaltene precipitation during natural depletion and miscible gas injection is a common problem in oilfields throughout the world. Therefore, predicting asphaltene phase behavior through thermodynamic modeling may help to control its precipitation and reduce the associated problems. In this work, a new modified cubic-plus-association (CPA) equation of state (EoS) was used to model asphaltene precipitation. This equation is based on a combination of a new physical part and an association term.

The new physical part has an evolved cubic equation of state with a new attractive term in this work. The results of the new modification of CPA EoS were compared with the experimental data of two oil samples (oil samples 1 and 2) that belonged to Moradi et al. The results showed that this modified CPA EoS can predict asphaltene precipitation with good accuracy.     

蒸发法处理稠油废水回用于注汽锅炉的新工艺

蒸汽辅助重力泄油(SAGD)或非SAGD的稠油/油砂开采工艺耗用大量的蒸汽,产生大量的含油废水.传统废水处理、回收和注汽蒸汽生产工艺流程复杂、回用水质差、劳动强度大、综合能效低.蒸发法处理稠油废水回用于注汽锅炉给水代替传统处理工艺在加拿大北阿尔伯达首次实现,并促成了汽包锅炉替代直流注汽锅炉的工艺优化.对蒸发法处理稠油废水生产高品质锅炉给水的工艺与传统处理工艺(石灰软化结合弱酸离子交换)进行了系统的比较和全面的经济性评价,同时对影响蒸发工艺的参数进行系统的分析,发现蒸发法稠油废水处理工艺具有流程简单、回用水质好、系统运行周期长、系统能耗低、经济性好等优势.进一步延伸该工艺可实现废水零排放.图7表1参7     

鄂尔多斯盆地长7段有机地球化学参数对致密油动用效果的响应

致密油层压裂效果及油气动用情况的评价指标和判识手段一般具有地区适用性。选取热解参数S ₁/S _T、PI值与饱和烃分子组成参数 \sum {\mathrm{C}}_{{\mathrm{20}}^{-}} / \sum {\mathrm{C}}_{{\mathrm{21}}^{+}} 、∑三环/∑五环、Pr/nC₁₇、Ph/nC₁₈对水平井开发目标层位长7₂亚段及相邻层位长7₁亚段和长7₃亚段进行比对,分析其实施压裂后致密油的动用效果。结果显示,参数 \sum {\mathrm{C}}_{{\mathrm{20}}^{-}} / \sum {\mathrm{C}}_{{\mathrm{21}}^{+}} 、∑三环/∑五环的比值存在明显分异;Pr/nC₁₇、Ph/nC₁₈参数也敏感地反映了原油直链和支链烷烃分子的差异渗流特征,表现为分子结构简单的轻组分相对含量在目标层位中明显降低。综合各有机地球化学指标特征,认为目标层位长7₂亚段的致密油受到优先动用,但采出程度不大。研究结果为鄂尔多斯盆地致密储层油气动用层位的精细判识提供了有效的敏感参数。     

Predicting the compressibility factor of natural gas

Knowing compressibility factor (z-factor) values of natural gases is the basis of most petroleum engineering calculations. Shortage of available experimental data for the specified composition, temperature, and pressure conditions encourages researchers to propose efficient equations for calculating z-factor values.

This investigation presents a useful empirical model for determining natural gases compressibility factor values. The advantages of this correlation are that it is explicit in terms of z-factor and the results of calculating compressibility factor values by this method reveal the supremacy of the new equation over the other widely used correlations.     

稠油油藏水平井多元热流体吞吐高效开采技术

水平井多元热流体吞吐高效开采技术是一项综合利用水平井、二氧化碳、氮气和蒸汽进行稠油开发的提高采收率新技术。根据稠油油藏的特点,对其进行了水平井多元热流体吞吐实验及数值模拟研究,揭示了其提高采收率机理。与常规蒸汽吞吐相比,水平井多元热流体吞吐高效开采技术具有3大优势:水平井可以提高注入能力与生产能力,且吞吐有效期长;二氧化碳能有效降低稠油粘度和残余油饱和度,提高驱油效率;氮气可以扩大注入蒸汽波及范围,降低注入蒸汽热损失。现场应用证实,该技术可有效提高蒸汽的利用效率,降低注入压力,提高油井产能,延长吞吐有效期,能够大幅度提高海上稠油产量。     

注有机极性气体开采稠油技术

针对储层薄、埋藏深的稠油油藏开发难度大及开采成本高的问题,在注溶剂萃取稠油技术（VAPEX）的基础上,提出向稠油油藏注入一种低饱和蒸汽压的有机极性气体PE提高采收率的采油技术。利用相态观察及黏度测定两种方法研究了该气体与稠油在气态和液态两种情况下的降黏效果。另外,还对比了该气体与VAPEX中常用烃类气体LPG对稠油降黏及萃取效果。实验结果表明:该气体在原油中具有很好的溶解性,能大幅度降低原油黏度;和LPG与稠油作用不同,该有机气体在液态状态下能大量分散稠油中的沥青,形成一种低密度低黏度混合相。现场应用表明注入该气体的措施井增产效果明显,因此,该注气技术可适用于一些埋藏深、油层薄、渗透性差和黏度高的稠油油藏。     

Implementation of CPA EoS for simultaneous solubility modeling of CO2 and H2S in ionic liquid [OMIM][Tf2N]

In this study, solubility of pure CO₂ and H₂S and their mixture in [OMIM][Tf₂N] modeled applying CPA EoS. CPA combines the SRK equation with an advanced association term, which is similar to that of SAFT. From a practical point of view, the target in the CPA project was to develop a thermodynamic model capable of describing complex equilibria of mixtures containing polar/associating chemicals through a simple procedure with respect to the SAFT.

The AAD% for binary systems, including H₂S+ IL and CO₂+ IL are 6.81, 5.21 respectively. Moreover, AAD% equal to 13.89 was achieved for the ternary system.     

Modeling of acid gases solubility in ionic liquid [BMIM][MeSO4] using CPA EoS

This work follows the thermodynamically modeling procedure to correlate the solubility of pure CO₂ and H₂S in [BMIM][MeSO₄]. Moreover, solubility of acid gases mixture was predicted. The bubble point pressure calculation method was applied in which CPA EoS is responsible for fugacity coefficients calculation of the components. The CPA EoS combines SRK and Wertheim's association term to handle non-ideal behavior of the polar and associating components.

The AADs% of H₂S+IL and CO₂+IL binary subsystems were calculated as 18.4 and 17.36 respectively. Moreover, AADs% equal to 27.26 and 6.74 were obtained for predicted partial pressures of CO₂ and H₂S, respectively.     

The CPA EoS application to model CO2 and H2S simultaneous solubility in ionic liquid [C2mim][PF6]

The CPA EoS was utilized for solubility modeling of pure CO₂ and H₂S and their mixture in [C₂MIM][PF₆]. The model is comprised of SRK EoS in addition to Wertheim's association term. Up to now, several associating models such as SAFT variants have been successfully applied to such systems. Considering the complexity and time consuming nature of SAFT EoSs, CPA can be a good alternative due to its accuracy and simplicity with respect to the SAFT.

The AAD % for binary systems including H₂S+ IL and CO₂+ IL are 11.78, 10.40 respectively. Moreover, the ternary system show AAD% equal to 16.51.