塔里木盆地塔河油田奥陶系原油及族组分碳同位素倒转成因分析

深入剖析塔河油田奥陶系原油与族组成的碳同位素倒转机理对于成藏演化认识和油气勘探均具有重要意义。对93件奥陶系原油及族组分在平面上与深度上的碳同位素变化特征分析表明：倒转程度在平面上由东向西逐渐加深,具有较好的规律性,艾丁地区、塔河主体区、托普台地区△δ¹³C_{沥青质-非烃}值分别为-0.73‰、-0.63‰、-0.58‰,在塔河9区及周边地区与南部盐下地区为正值。艾丁地区和塔河主体区的部分井原油δ¹³C_饱和烃与δ¹³C_全油发生了倒转;δ¹³C_沥青质与其他组分碳同位素及δ¹³C_全油在塔河油田不同区域发生了不同程度的倒转;而在深度上倒转分布与原油的埋藏深度缺乏相关性,由埋藏深度引起的热力作用不是造成塔河油田奥陶系原油族组分中沥青质碳同位素与其他组分碳同位素倒转的主要原因。结合原油族组分含量、饱和烃色谱总离子图,综合分析认为原油及族组分碳同位素倒转与前期成藏之后地层抬升引起的生物降解和油气的多期次充注有关,前期充注的原油中烃类组分多被微生物降解,而沥青质不易被降解得以保留,由于成熟度低,碳同位素值较低;而后期充注的高—过成熟度油中沥青质含量很低,以其他组分尤其是饱和烃为主,由于成熟度高,碳同位素值较高,甚至大于早期充注油的沥青质碳同位素值,使混合油中出现沥青质碳同位素与其他组分碳同位素倒转的现象。因此,塔河油田奥陶系原油成藏过程及其成藏之后的次生变化是碳同位素倒转的主要原因。     

注天然气油井沥青质析出规律研究

目的 解决东河区块原油在注气开采过程中沥青质沉积堵塞井筒问题.方法 采用高温高压固相沉积规律测试装置,基于光散射理论,研究了温度、压力、气油比等因素对沥青质析出特征的影响.结果 温度升高会增加沥青质在原油中的溶解度,促进原油稳定;等温降压过程中,沥青质随着压力降低逐渐析出,在泡点压力附近达到最大析出量,发生沥青质沉积堵...     

地层原油组成差异对高压物性参数的影响

地层油高压物性参数主要受温度、压力等因素的影响,而地层油自身的组成也对其有着重要影响。对S48井、G942井和F154井的地层油进行了一系列的高压物性实验研究。结果表明：相同气油比,原油含蜡量越高,地层油泡点压力越高,体积系数越大;当压力高于泡点压力时,原油含蜡量越低,溶解气量越多,地层油体积系数和密度受压力的影响越显著;含蜡量越高,体积系数和密度受压力的影响越小。含蜡量高的地层油溶解天然气后的降黏效果明显好于含蜡量低的地层油。     

A Compositional Reservoir Simulation and Experimental Investigation of Asphaltene Onset Pressure

Asphaltene precipitation is one of the most common problems in many reservoirs and may lead to many safeties operational issues which affects on oil recovery; therefore, identifying start of asphaltene activation is known as a key parameter to control production efficiency. This study includes predicting onset pressure with Multiphase Flash test and compare its result with experimental data generated by Asphaltene Static Apparatus. Safety pressure was obtained by performing Multiphase Flash test for each component. In order to prevent adsorption, mechanical entrapment, and blockage, reservoir pressure must be higher than this safety pressure. SARA test is widely used to identify the fraction of crude oil that affect the asphaltene stability. IP143 standard test was used to measure precipitated asphaltene. Natural depletion test was designed at four steps, including 4400, 3000, 1550, and 1020 Psia and reservoir temperature is 205°F. It was seen that with decreasing pressure from reservoir pressure to saturation pressure asphaltene precipitation from PVT cell was increased and at pressures below saturation pressure with pressure reduction, asphaltene precipitations was decreased. Also it was concluded that above saturation pressure solubility model is dominant and below saturation pressure colloidal model is dominant. The results of IP143 show that initial content of asphaltene are 12.8%. SARA test result shows this kind of fluid located at unstable asphaltene precipitation region. Comparison of safety pressure between Multiphase Flash test and experimental data are investigated and discussed. Onset pressure of 18000 Pisa was obtained from Multiphase Flash test, which is in good agreement with experimental result.     

混合原油的相容性

 为探讨混合原油相容性规律,将3种不同基属的原油,新疆塔河(Tahe)原油、委内瑞拉波斯坎(Boscan)原油、哈萨克斯坦库姆克尔(Kumkol)原油进行混合,采用显微镜观察混合原油的相容性,并根据稳定性参数IN、SBN考察混合原油的相容性变化规律。结果表明,将石蜡基的库姆克尔原油分别掺入塔河原油和波斯坎原油的体积分数为60%和85%时,出现不相容现象。根据所测原油和混合原油的稳定性参数IN和SBN可知,随着轻质石蜡基的库姆克尔原油掺入塔河原油或波斯坎原油比例的增大,混合原油对沥青质的溶解能力逐渐下降,最终导致不相容现象发生。从原油组成来分析,两性质差异较大的原油混合时,体系中饱和烃含量增多、芳香烃和胶质含量减少是致使沥青质絮凝的原因,而沥青质的n(H)/n(C)低、芳碳率(fA)高是混合体系更易絮凝的重要原因。     

塔河油田超深自喷井流态特征分析

针对塔河油田油藏埋藏深、原油粘度高、井筒热损失大导致自喷困难的实际问题，根据热量传热原理和两相流动理论，建立了自喷井中产出液沿井筒流动与传热的热力学模型。运用该模型计算了塔河油田5口稠油井产出液沿井筒的温度和压力分布。计算结果表明。随着产出液沿井筒的举升。压力逐渐减小，温度不断下降。当温度下降到一定数值时。原油粘度明显增大，即对应原油的拐点温度出现。因此，可以根据流态特征来估计该原油的拐点温度，为选择合适的降粘方法和降粘深度提供了技术指导。     

塔河油田沥青质稠油成因分析及防治技术

塔河油田TK235、TK305等井陆续出现沥青质稠油沉积堵塞油管造成停产,对生产造成了严重影响。针对此类问题,文中对塔河油田原油中沥青质的沉积问题进行了综合研究,形成了有效的沥青质稠油沉积堵塞防治技术。通过对塔河油田沥青质原油组分进行分析,结合沥青质沉积堵塞物成分的分析,发现沥青质沉积主要是由于原油组分在举升过程中的环境条件变化所导致,从而开发了掺稠油、掺改性稠油（稠油＋沥青分散稳定剂）等治理工艺．试验结果表明：这些工艺较好地解决了沥青质沉积堵塞油管的问题,实现了油井的正常生产,并在现场应用中取得了良好的效果。     

委内瑞拉MPE-3区块超重油冷采过程中泡沫油开采机理

针对超重油沥青质含量高、原油重度高等特点,研究了水平井溶解气驱冷采的开采机理,包括冷采过程中泡沫油的形成机理、非常规PVT特性与驱替特征。实验结果表明,当油藏压力低于泡点压力时,原油中形成许多微小气泡,这些微小气泡能够长时间滞留在油相中,使得这种原油表现出与常规溶解气驱许多不同的特征;泡沫油的作用与油藏衰竭速度、油层压力下降水平及围压等因素有关。使用水平井冷采技术能够获得较高原油产量和采收率。     

环烷酸对高沥青质含量稠油乳状液稳定性的影响

以高沥青质塔河稠油为研究对象，从中分离出沥青质，配制成模型油乳状液；从辽河、苏丹原油中分离出天然羧酸，考察原油中天然羧酸对塔河沥青质模型油乳状液稳定性的影响。 结果表明，天然羧酸可以起到类似于胶质的作用，通过对沥青质的分散作用，降低沥青质模型油乳状液的稳定性。 有机羧酸和烷基芳磺酸可以起到与天然羧酸类似的作用，而且烷基芳磺酸降低模型油乳状液稳定性的能力更强。     

原油沥青质初始沉淀压力测定与模型化计算

温度、压力及组成的改变均会造成原油中沥青质产生沉淀,导致储层伤害和井筒堵塞。文中通过自主研制的固相沉淀激光探测系统,用透光率法首次测定了伊朗南阿油田原油样品在不同温度下的沥青质初始沉淀压力;同时利用Nghiem等建立的沥青质沉淀预测的热力学模型对油样沥青质初始沉淀压力进行计算,并与实验结果拟合。结果表明：利用透光率法测定该油田油样,在44,80,123℃下的沥青质初始沉淀压力点分别为42.8,39.7,35.2 MPa;沥青质初始沉淀压力随着温度的升高,在井筒温度范围内呈线性关系。模型计算与实验结果误差不超过15%,所以利用Nghiem模型对原油沥青质的初始沉淀压力进行预测是可靠的。     

塔河油田成藏期次的地球化学示踪研究

应用油藏地球化学的方法对塔河油田的成藏期次进行了探讨。塔河油田稠油正构烷烃分布完整,但色谱基线不同程度抬升;原油非烃和沥青质碳同位素偏轻,族组成碳同位素发生倒转;原油中普遍含有25-降藿烷。这些特征表明该区油藏经历了至少两期成藏过程,早期充注原油遭受生物降解作用后又受到高成熟原油充注。塔河油田天然气为典型的油型气,成熟度较高,为成熟—过成熟阶段产物,亦显示了两期充注的特征:早期充注的为典型的原油伴生气,充注时间与后期原油的充注时间相同;晚期充注的为高温裂解气,充注方向为自东向西。因此,塔河油田至少存在着3次油气充注过程。      

Inhibition of asphaltene flocculation in light crude oil: effect of pressure,temperature and inhibitor concentration

Abstract

In this study, a light crude oil sample was taken from Hassi Messaoud field to characterize its physicochemical properties. The asphaltene flocculation onset was determined in the dead oil by Flocculation Titrimeter equipment. The petroleum resins have been extracted from the same crude oil and tested as an inhibitor of asphaltene flocculation then their efficiency has been studied at different conditions of pressure and temperature. The results point out that the extracted resins may have two different effects on the onset point depending upon the operator conditions and the concentration of the added resins to crude oil.     

高压注烃类气体过程中沥青质初始沉淀压力试验研究

为预防注烃类气体提高采收率过程中产生沥青质沉淀,对沥青质初始沉淀压力进行了试验研究.在分析注烃类气体过程中沥青质沉淀机理的基础上,通过自主研发的固相沉积激光探测装置,采用透光强度法测定了原油样品在不同温度下高压注气过程中沥青质的初始沉淀压力,并确定了沥青质沉淀的深度.试验得出,原油沥青质初始沉淀压力随温度升高而下降,测得44,80和123 ℃温度下原油的沥青质初始沉淀压力分别为44.1,39.7和35.2 MPa;每注入物质的量分数为1%的烃类气体,试验油样的沥青质初始沉淀压力升高0.5~0.6 MPa;井筒温度压力曲线与沥青质沉淀相包络线相结合预测井筒中出现沥青质沉淀的深度在1 800 m左右,与现场情况吻合较好.研究表明,原油中沥青质初始沉淀压力与注气量之间呈线性关系,可为现场注气驱油预防和清除沥青质沉积物提供理论依据.      

The Effect of Temperature and Pressure on the Reversibility of Asphaltene Precipitation

A lot of hindrances are seen in petroleum operation, production, and transportation as a results of factors that related to asphaltene precipitation. It has great importance to investigate the reversibility of asphaltene precipitation under changes of effective factors on thermodynamic conditions such as pressure, temperature, and composition. In the present work the reversibility of asphaltene precipitation under changes of pressure and temperature was investigated for two kind of Iranian heavy oil. The stability test shows these samples are located at unstable region in aspect of asphaltene precipitation. The experimental procedure includes two parts, (a) decreasing pressure from initial reservoir pressure to near saturation pressure and surveying asphaltene content hysteresis with redissolution process at reservoir temperature, and (b) investigation of precipitated asphaltene in both precipitation and redissolution processes at different temperature and reservoir pressure. At each step IP143 standard test was used to measure precipitated asphaltene. It was concluded that above bubble point pressure, asphaltene precipitation is nearly reversible with respect to pressure for both samples and it was partially reversible with respect to the temperature for sample A, and accordingly pressurizing is acceptable method for solving the problem in both heavy asphaltenic crude oil samples and increasing temperature is acceptable method for solving asphaltene problem in crude oil sample A. Also density measurement of flashed oil confirmed that there is a little hysteresis in asphaltene content during redissolution and precipitation processes.     

柱色谱分离法预测塔河常压渣油脱沥青油杂质含量的研究

塔河原油是一种沥青质含量高、残炭高、金属含量高、酸值高的重质原油,为避免传统加工过程中的高温腐蚀和塔河渣油进催化裂化装置的高残炭、高金属含量等问题,考虑将塔河原油经常压闪蒸后的渣油直接作为溶剂脱沥青的原料。采用挂片失重试验对塔河原油的腐蚀性进行了研究,同时对适宜闪蒸温度下的常压闪蒸渣油进行了六组分分离,并对各组分的化学性质和结构参数进行了分析。结果表明:53.89%的硫、86.97%的氮、98%以上的镍、钒金属存在于胶质和沥青质组分中;随着组分加重,芳碳率fA增加,H/C原子比、环烷碳分率fN和芳香环系缩合度参数HAU/CA减小;将塔河常压闪蒸渣油在不同柱色谱馏出油收率下的杂质脱除率曲线与溶剂脱沥青中试结果对比发现,两者有较好的相似度,表明采用柱色谱分离方法可以在一定程度上来预测溶剂脱沥青过程不同脱沥青油收率时的杂质含量,可指导塔河常压闪蒸渣油溶剂脱沥青过程的操作。     

Deposition and flocculation of asphaltenes from crude oils

A crude oil has four main constituents: saturates, aromatics, resins, and asphaltenes. The asphaltenes in crude oil are the most complex and heavy organic compounds. The classic definition of asphaltenes is based on the solution properties of petroleum residuum in various solvents. Asphaltenes are a solubility range that is soluble in light aromatics such as benzene and toluene, but are insoluble in lighter paraffins. The particular paraffins, such as n-pentane and n-heptane, are used to precipitate asphaltenes from crude oil. Deposition of asphaltenes in petroleum crude and heavy oil can cause a number of severe problems. The precipitation of asphaltene aggregates can cause such severe problems as reservoir plugging and wettability reversal. Asphaltenes can precipitate on metal surface. Cleaning the precipitation site as well as possible appears to slow reprecipitation. To prevent deposition inside the reservoir, it is necessary to estimate the amount of deposition due to various factors. The processes can be changed to minimize the asphaltene flocculation, and chemical applications can be used effectively to control depositions when process changes are not cost effective. Asphaltene flocculation can be controlled through better knowledge of the mechanisms that cause its flocculation in the first place. The processes can be controlled to minimize the asphaltene flocculation, and chemical applications can be used effectively to control depositions when process changes are not cost effective.     

The Structural Characterization of Saturate,Aromatic, Resin,and Asphaltene Fractions of Batiraman Crude Oil

Abstract

The structural characterization of fractions of Batiraman crude oil, which is the heavy crude oil from a field in the southeastern part of Turkey, was investigated. Batiraman crude oil and its saturate, aromatic, resin, and asphaltene (SARA) fractions were seperated. Treatment of crude oil with n-heptane provided the separation of asphaltene. Maltene was collected by evaporating the n-heptane from the filtrate. Then, maltene was separeted into saturates, aromatics, and resins by SARA technique. Maltene was separated into saturate, aromatic, and resin fractions using column chromatography. SARA fractions were quantified on a weight percent basis. Fractions of Batiraman crude oil were characterized by elemental analysis, proton nuclear magnetic resonance (¹H NMR) analysis, electrospray ionization mass spectrometry (ESI-MS), and Fourier transform infrared (FTIR) spectroscopy techniques.     

Polydispersity of heavy organics in crude oils and their role in oil well fouling

In this report, the polydisperse data of heavy organic fractions of crude oil and solid deposit were produced to investigate the causes of deposition in oil wells. The oilfields of the study have experienced, for several years, shutdowns and decrease in the production ratios due to heavy organics deposition. Several measures such as mechanical cleaning and periodic aromatic washes have been adopted to maintain the production level; nevertheless the costs associated with these procedures are very high.The SARA method was employed to separate the samples into four distinct fractions, namely Saturates, Aromatics, Resins and Asphaltenes. The total asphaltene content of the crude oil samples was determined using n-pentane, n-heptane, and n-nonuse as the precipitating solvents. Polydispersity and molecular weight of each fraction have been further characterized by Gel Permeation Chromatography (GPC). The presence of diamondoids in the solid deposits was also investigated by GC-MS. This technique has been carried out on various crude oil samples collected from an oil field.The results provided useful information on the interaction between the various heavy organic species responsible for the deposition phenomena. Solid samples from different wells resulted in similar composition concluding that these crude oils undergo similar deposition mechanisms. These studies showed that the crude oils produced from different wells in this oilfield are very similar in nature. The asphaltenes contained in some of the crude oil samples displayed a rather strong tendency to self-associate; they also render the highest amounts of precipitation. While diamondoids and alkyl-substituted diamondoids were confirmed to be present in the crude oils produced no evidence was found of their occurrence in the deposits.The polydispersity analysis procedure presented here provides a good understanding of the overall behavior of the species that precipitate and also of the interactions among these species. It is concluded that while most of the heavy organics contained in these crude oils may produce precipitates, asphaltene is the major cause of flocculation of the precipitates, which may result in deposition and plugging of oil-producing wells.     

原油沥青质沉积抑制及解堵技术研究进展

世界范围内原油沥青质沉积问题多有发生,对原油开采及后处理带来极大困难,研究沥青质沉积抑制技术和解堵技术具有非常重要的意义。综述了油井沥青质沉积抑制技术,包括调整生产参数和添加化学抑制剂,如天然脂肪酸类有机物、含苯环的表面活性物质、植物油类或油品加工产物、离子液体、金属氧化物纳米粒子。介绍了沥青质沉积解堵技术,包括机械法、化学法、热力法、生物法、外力场、复合解堵法等。对沥青质沉积抑制及解堵技术的未来发展趋势进行了分析,需提前对油井或管道做好评估、分析、预测,深入研究沉积抑制及解堵机理,明确不同技术的适应性,加强复合解堵技术的研究与应用。     

稠油油溶性降黏剂结构与性能的关系

研究了塔河稠油沥青质含量与稠油粘度的关系。根据稠油中沥青质含量较高且极性较强,粘度主要是由沥青质聚集体引起的研究结果,针对超稠油特性研制了极性聚合物作为油溶性降黏剂主剂,表面活性剂作为助剂的复合配方。通过调控主剂分子结构中极性基团的比例来改变其极性的强弱,通过选择助剂适合的烷基碳链长度、芳香环数以及支化甲基数,达到协同增效的目的。结果表明:当主剂极性大小适当,助剂结构适当时具有协同增效作用。复合降粘剂对塔河十区、十二区稠油降黏效果显著,加剂量质量分数0.5%时,降黏率大于30%,节约稀油率约35%。