Oily Wastewater Treatment through a Separation Process Using Bubbles without Froth Formation

Abstract

This study seeks to investigate the use of a surfactant derived from coconut oil in the recovery process of organic compounds from oily effluents. To evaluate its efficiency in oil removal and its optimal concentration for each oil/water ratio, experiments were carried out using water/oil emulsions (50, 100, 200, and 400 ppm of oil) and produced water (50 ppm) in a small-scale column. According to these experiments, it was verified that there is an optimum surfactant concentration for each emulsion, and for produced water the extraction efficiency reaches a maximum value (80%) at a surfactant concentration of 0.1 g/L^?1.     

Reduction of Oil and Gas Coning Effects by Production Cycling and Horizontal Wells

Abstract

This article investigates by simulation, coning mitigation during oil production from thin oil rim reservoirs using horizontal wells and production cycling. Production cycling is an operating technique in which the well is produced and then shut in for periods of time. During the shut-in periods, the cone reduces. This work suggests that production cycling delays water breakthrough. However, once breakthrough occurs, the well must be put on continuous production due to difficulties in unloading the wellbore and with the assistance of gas lift.     

Recovery Improvement Using Water and Gas Injection Scenarios

Abstract

Water and miscible gas injection scenarios are considered in an Iranian oil reservoir for the purpose of recovery improvement. Firstly reservoir fluid modeling and modeling of a slim tube test were performed. Then, water alternating gas (WAG) injection was evaluated by optimizing the WAG half cycle and WAG ratio. Alternatively, hybrid WAG and separate injection of water and gas in the top and bottom of the reservoir were also investigated. The numerical simulation results showed that the optimum WAG, with half cycle of 1.5 years and WAG ratio of one, gave the highest recovery factor. Moreover, economic evaluation of these scenarios indicated that WAG had the highest net present value and was the most interesting scenario for improving the recoveries.     

The Effect of Temperature and Impeller Speed on Mechanically Induced Gas Flotation (IGF) Performance in Separation of Oil from Oilfield-Produced Water

Abstract

The effect of temperature and impeller speed on the performance of induced gas flotation (IGF) systems for the removal of oil from produced water in different ranges (5–300 g/L) of total dissolved solids (TDS) was investigated in a pilot plant study. Furthermore, it was evaluated whether the IGF pilot plant effluent could reach the 15 mg/L outlet oil content as required by Article VI of the Kuwait Convention for Persian Gulf region, before being discharged to the sea. The results showed that oil removal efficiencies up to 90% could be reached at high temperature (80°C) in just one single flotation cell without adding any chemicals. Flotation unit, however, should be followed by at least one more flotation cell in series in order to guarantee the Kuwait Convention marine pollution discharge standard for the effluent oil content.     

CHATACTERIZNTIAN OF SOME IRAQI ASPHALTS. II. NEW FINDINGS ON THE PHYSICAL NATURE OF ASPHALTENES

ABSTRACT

Uapcur pressure csmometry (UPO) and viscometric technique were used to reveal the true molecular weight of asphaltenes and the degree of association in solvent of different polarities at different temperatures. The number average malecular weight of unassociated asphaltenes was found to be 935 g/mcl. In n' trobenzene at 120 C. The degrees of association were determined from UPO in benzene at 37, 45, 60 C, in chlorobunzene at 37, 45, 60 and 90 C. in THE at 37, 45, 60 C and in nitrobenzene at 90 C. The degree of association determined by ulscometric method at 37, 45 and 60 C, in these soluents were found to be in approximate agrement with that found bv UPO. Data derived by means of ulscometric and osmometric methods consolidated the recognition that asphaltenes could be similar to macro-molecules structurally.     

A Study on Mass Concentration Determination and Property Variations of Produced Polyacrylamide in Polymer Flooding

Abstract

Because injected polyacrylamide often quickly breaks through to production wells during polymer flooding, its mass concentration determination is very significant. However, due to the variations of relative molecular mass and degree of hydrolysis of produced polyacrylamide, the conventional determination methods, including viscosimetry and starch-cadmium iodide colorimetry, are no longer suitable for determining its real mass concentration. A new determination method—ultrafiltration concentration film drying—is proposed and developed in this article. By purifying and concentrating produced polyacrylamide solution using an ultrafiltration system and then dehydrating water to a constant weight, this method can determine the mass concentration directly. This method has been evaluated in the laboratory and compared with two conventional determination methods, verifying its adaptability and high accuracy. The produced polyacrylamides from three different polymer flooding blocks have been determined using this new method. The results show that the relative molecular mass of produced polyacrylamide decreased greatly and its degree of hydrolysis increased obviously. The reasons and differences have been also analyzed. These corresponding variations make the results determined by the conventional methods much lower than the actual results, and it is implied that the previous methods need to be improved or replaced.     

Features of the composition and properties of crude oil from the Bavly oil field of the Volga-Ural oil and gas province

Abstract

The article presents the results of a comparative analysis of the composition and physicochemical properties of crude oils produced from different horizons of the Carboniferous and Devonian deposits of the Bavly oil field (Tatarstan, Russia), including the Zavolzhsky and the Dankovo-Lebedyan horizons attributed to the domanic deposit. It is shown that oils from the domanic deposit are similar to Carboniferous oils by composition and properties but have unique features. A cluster analysis of the obtained results was carried out.     

污水配制聚合物研究

针对油田产出污水外排的问题，在喇嘛甸油田开展了利用油田产出污水配制聚合物的可行性研究。在污水聚合物溶液性质研究、渗流特性研究及岩心驱油实验基础上，进一步开展了污水聚合物体系油层工作粘度和微观分子形态研究，对污水聚合物体系及驱油机理有了新的更加深入的认识。室内研究表明：污水聚合物体系与油层配伍性好，在油层中有更高的工作粘度；聚合物在污水条件下以枝状结构为主，带状和网状结构为辅。在喇嘛甸油田北西块开展的污水稀释超高相对分子质量聚合物驱油现场试验也表明：污水聚合物体系注入过程中吸水剖面得到较好调整，污水聚合物驱是完全可行的，是解决油田污水外排的有效途径。     

A Novel Approach to the Gas-Lift Allocation Optimization Problem

Abstract

Because compressed gas is a scarce and expensive resource, allocating an optimal amount of gas injection to a group of wells to increase the oil production rate is an important optimization problem in the gas lift operation. In this article, a particle swarm optimization algorithm is employed to assign an optimum gas injection rate for each individual well. Also, a new gas lift performance curve-fit that can reduce the time and volume of the computation is suggested. Finally, the algorithm is tested on five wells in an Iranian oil field.     

聚合物驱采出污水深度处理的实验研究

以大庆某采出液处理站含聚污水为研究对象,应用UV/H2O2/O3组合对二次除油、过滤后的污水进行了处理实验,实验分析了H2O2、O3投加量、紫外灯强度、初始pH值以及处理时间对HPAM去除率影响,确定了合理的组合参数量;结合初始污水中含油量变化对聚合物和污油去除率的影响进行了实验,确定了初始污水含油量范围。并对处理前后污水对岩心渗透率伤害程度进行实验,结果表明,应用高级氧化处理技术处理后的含聚污水水质可以满足污水回注油层要求,在现场比较经济可行。     

模拟油气田采出水的腐蚀性实验研究

以模拟的油气田采出水对碳钢进行腐蚀实验,通过改变溶解O2含量、溶解盐浓度、H2S浓度、CO2浓度以及腐蚀反应时间等,考察了各种腐蚀介质对碳钢的腐蚀作用,得出了它们对碳钢腐蚀速率的影响规律。碳钢的腐蚀速率随溶解O2含量、溶解盐浓度以及CO2分压的增大而逐渐上升。当H2S浓度增大时,采出水对碳钢的腐蚀速率先增大,后减小,最后趋于稳定。饱和O2的采出水对碳钢的腐蚀速率随腐蚀时间的增加而逐渐降低。而含H2S采出水对碳钢的腐蚀速率受腐蚀时间的影响不大,随腐蚀时间的增加略有降低。同时,文章还对腐蚀介质的腐蚀机理进行了探讨,并对今后的研究工作提出了建议。     

中原油田文二联地区注入水动态结垢趋势试验研究

采用盘管式动态结垢模拟试验仪对中原油田文二联地区产出水、室内处理水、现场处理水以及混配水进行了动态结垢模拟试验。结果表明，文二联产出水在地层温度下，有一定量的沉淀结垢物形成；室内处理水也有少量的沉淀结垢物形成，与产出水相比，沉淀结垢量要低一些；现场处理水基本沉淀结垢物产生；产出水与现场处理水混配后，沉淀结垢量明显上升，但与产出水和室内处理水的配伍性相比，明显好转；温度高，盐析现象严重是引起沉淀量上升的主要原因。     

Innovative reuse of drinking water sludge for the treatment of petroleum produced water to enhance oil recovery

Using treated petroleum produced water (PPW) as injected water, for enhancing oil recovery, is important in petroleum industry. The process of water reuse is a cost-effective method. On the contrary, injection of inadequately treated water could induce scale formation. In the present study oil-free petroleum produced water (PPW) was treated to obtain water without scale tendency by using the water treatment sludge (WTS) produced from the Drinking Water Treatment Plants (DWTP). The WTS is usually accumulated in the DWTP as solid useless solid wastes. The characterization of the washed and dried WTS was investigated extensively by scanning electron microscope (SEM), Energy Dispersive X-Ray (EDAX), Dynamic light scattering (DLS), and Surface area analyzer. It was found that the average particle size of WTS is 47.34 nm. The main constituents of the WTS are MgO, Al₂O₃, SiO₂, CaO, and Fe₂O₃. This WTS was reused for the treatment of oil-free PPW, where the chemical and physical characteristics of PPW before and after treatment were determined. The present study showed that the optimum WTS dose was 3 g/l at which the salinity, alkalinity, TDS, conductivity, hardness, cations and anions of the PPW were significantly decreased. The overall results revealed that by decreasing the cations and anions of PPW, the later has no any tendency to form scale. Therefore, the treated PPW could be used again to enhance oil recovery without any concern of scale formation, water-saving, as well as protecting the environment from the discharge of such polluted water.     

靖一联采出水处理及回注工艺技术研究与应用

主要针对靖一联絮凝罐+精细过滤处理工艺处理后水质达不到回注标准的现状,借鉴油一联微生物处理的成功经验,通过室内菌种筛选,优选出了适合靖一联采出水的微生物菌群,并在现场进行了微生物处理工艺改造,使靖一联采出水处理水质得到了明显改善,达到了油田采出水的回注要求,实现了靖一联全部采出水的有效回注,节约了大量的清水资源和运行费用。     

油田污水抗菌沸石处理效果评价

利用液相离子交换法,在天然沸石和人工沸石上吸附金属离子Zn2+、Cu2+和Ag+,制成抗菌沸石,并用其对采出污水进行浸泡处理,进一步评价了用该污水配制聚合物溶液的热稳定性。实验结果表明,用Ag+抗菌沸石处理的污水配制聚合物溶液黏度较未处理污水聚合物溶液的高,Ag+抗菌沸石处理效果也要优于Zn2+和Cu2+抗菌沸石。     

海上聚合物驱油田污水处理剂的开发利用

聚合物驱污水中含有大量水解聚丙烯酰胺,由于带有大量的羧酸根而带负电荷,处理难度大。目前,主要的商用清水剂为聚阳离子类,如阳离子聚丙烯酰胺、聚铝等,其机理是利用静电中和作用,实现油滴聚集上浮从而净化水质,但在处理的同时会导致大量含聚合物的油泥产生,引起生产流程的堵塞。为了解决该问题,研制了非离子类清水剂,并在海上平台污水处理流程中进行了加注,观察处理效果,加注后水质稳定,满足回注要求。下一步将扩大试验规模,评估并指导新型药剂的研制。     

Black Oil and Compositional Reservoir Simulation for Increasing the Recovery Performance of an Iranian Fractured Carbonate Reservoir

Abstract

Naturally fractured reservoirs contain a significant amount of world oil reserves. Accurate and efficient reservoir simulation of naturally fractured reservoirs is one of the most important, challenging, and computationally intensive problems in reservoir engineering. Black oil and compositional reservoir simulators have been used to determine the reservoir management and production strategies to increase the oil recovery from a low-porosity, low-permeability fractured carbonate reservoir, with an average matrix permeability of 0.8 md, average fracture permeability of 500 md, and an average matrix porosity of 10%. This reservoir is a candidate for an enhanced oil recovery (EOR) process, because the reservoir production rate has been declined due to increasing the water cut as a result of rising the water oil contact. The injection techniques that have been considered in this study for black oil model include (a) gas injection, (b) water injection, and (c) simultaneous water alternating gas injection and for the compositional model include (a) dry gas injection, (b) CO₂ injection, and (c) N₂ injection. Simulation results show that CO₂ injection has the maximum oil recovery between the EOR scenarios.     

石西油田集输系统防垢研究

石西油田集输系统出现结垢问题 ,在详细分析采出水水质和结垢物组分的基础上 ,对结垢原因进行了分析。结果表明采出水有两种水型 ,这两种水为不相容水 ,混合后易结垢 ;石南油田采出水与石西采出水混合后结垢量增加 ;提出的防垢措施在现场得到应用     

油田采出水新型处理工艺技术应用及评价

随着油田开发进入中后期,采出水量逐年增加,采出水出路成为制约油田"可持续"发展的一项重大难题。而实现采出水合格处理后有效回注,不仅是解决油田采出水出路的根本途径,也是国家"节能减排、环保治理"工作的重点。     

含聚污水处理系统HPAM形貌特征及胶状产物成因

利用原子力显微镜和环境扫描电镜,对污水处理流程各节点中产出的聚合物微观形貌进行观察。结果表明,油井产出聚合物为多层次立体网状结构,经过破乳剂、清水剂等药剂作用后,产出的聚合物呈线团状缠绕结构,在进一步物理化学交联作用下,大量产出聚合物析出,未被析出的聚合物分子尺寸、浓度、链段长度等大大减小。破乳剂和清水剂对产出聚合物的脱稳和絮凝作用,导致产出聚合物絮凝沉降,絮凝沉降过程中将油珠和其他悬浮物聚集,是导致大量胶状产物形成的主要原因。该项研究成果对锦州9-3油田污水处理系统的正常运行和水质稳定控制技术的研究具有重要的指导作用。