注水开发油藏的储层保护技术

通过向地层注水来保持油层压力,进而延长开发时间,提高采收率,是一种常见且经济的开发方式。但是,在油藏注水开发过程中,由于技术、管理等方面的原因,存在着损害地层的问题。因此,注水开发中必须从技术、管理等方面入手,采取有效措施保护储层免受污染。本文通过对采油、注水过程中储层损害机理分析,提出防止储层污染的方法和处理注水过程中地层损害的方法。     

宝浪油田提高原油采收率技术研究

分子膜驱油技术是目前石油业提高采收率研究的一个重要方向。其核心就是它与储层岩石接触后,由于在岩石表面的吸附、滞留和捕集作用,使储层表面的润湿性发生变化,从而达到驱替残余油、提高原油采收率的效果。例如由强亲油向弱亲油、中性,甚至亲水性变化时,不仅原油的采出程度有大幅度的提高,而且对于低渗透储层,特别是超低渗透的储层来说,也由于注入性和注入能力的提高而可以进行理想的水驱或化学驱。本文结合宝浪油田低渗储油层的实际情况通过对分子膜剂性能的评价,筛选出了适合宝浪油田低渗储层的分子膜剂类型和浓度。     

co2驱提高采收率技术研究进展

随着一些油田开发进入后期,注水开发以及一些三次采油技术已经不能再提高采收率,这时CO2驱作为一项提高原油采收率的技术在现场得到了广泛应用。目前,此项技术在美国、加拿大等国的应用已较成熟。我国对该技术的研究相对较晚,对该工艺还需要深入研究。在国内,随着CO2气源的发现,此项技术正在被越来越多的油田应用。本文在调研国内外大量文献资料的基础上,阐明了CO2提高原油采收率的机理,注水方式以及CO2驱提高采收率的研究现状及进展,并总结了适合CO2驱目标储层的筛选标准。     

碳酸盐岩油藏储层渗流特征实验研究

碳酸盐岩储层流体渗流规律与常规砂岩储层明显不同,此类储层开发过程中,存在生产井压力和产量下降快、采收率低等问题。为此,本文通过两相驱替实验分析了Sar油田储层岩心渗流规律、洗油效率及其主要影响因素。通过实验研究得出,当致密碳酸盐岩储层不存在裂缝时,储层水驱采收率仅有30%,而当存在一定裂缝时,由于储层平均渗透率增加,且存在基质和裂缝之间的渗吸作用,相比无裂缝油藏采收率可提高3%～10%,这表明,碳酸盐岩油藏在进行水驱开发时,存在一定裂缝的储层的水驱开发效果要优于不存在裂缝的碳酸盐岩储层。     

非常规油气开发储层改造技术进展

本文通过梳理非常规油气储层改造技术的发展历程,总结了储层改造技术主要新进展,认为非常规油气储层改造技术主要向深化裂缝起裂及延伸机理研究、降低支撑剂及多功能压裂液成本、提高裂缝控藏程度、大幅提高采收率方向发展。     

复杂断块油田聚合物驱注入参数优化

通过利用"正交表"实现双高阶段油田聚合物驱多参数多水平方案筛选,大大减少了数值模拟筛选的工作量并且提供可靠的试验结果,提高工作效率。并在此基础上开展四种段塞组合的数值模拟筛选工作,根据不同方案的采收率增量和吨聚合物增油量优选最适合的注入方式,保证提高油藏采收率的同时兼顾经济,预计可提高采收率7.02%,含水可降低可降5.5%,为现场实施方案提供可靠的理论依据。     

高含水油田聚/表二元驱注入参数优选研究

参照适合开展化学驱油藏的筛选标准筛选砂体开展聚/表二元驱,通过利用正交设计开展化学驱多参数多水平方案筛选,大大减少了数值模拟筛选的工作量并且提供可靠的试验结果,提高工作效率。并在此基础上开展4种段塞组合的数值模拟筛选工作,根据不同方案的采收率增量和吨化学剂增油量优选最适合的注入方式,保证提高油藏采收率的同时兼顾经济性,预计可提高采收率16.87%,含水可降低8.5%,为现场实施方案提供可靠的理论依据。     

储层改造技术的现状与发展建议

油田开发过程中,对储层实施改造技术措施,促进油田开发的进步。对储层实施解堵技术措施,提高单井的产油量。对注水开发油田进行整体的储层改造,提高水驱的开发效率。通过细分层段的开发,提高油层的动用程度,为提高油田的最终采收率提供保证。     

纳米流体对储层润湿性反转提高石油采收率研究进展

储层岩石的润湿性对于石油采收率至关重要,近年来纳米流体润湿反转技术在提高石油采收率方面的应用得到了广泛关注,并取得了一系列成果。本文首先介绍了利用纳米流体对储层润湿性反转在提高石油采收率方面的应用,包括提高水驱效率和降压增注,其次归纳了润湿性变化的实验评价方法并分析影响纳米流体润湿反转效果的因素,表明纳米材料性质（类型、尺寸、浓度）和地层环境（温度、矿化度）均有不同程度的影响。然后阐述了纳米流体改变储层润湿性的机制,认为其包含纳米流体润湿铺展和纳米颗粒岩石壁面吸附的双重机制。最后指出运用此技术存在的问题和难点,并对以后的研究方向进行了展望。     

X油田特高含水期低矿化度水驱提高采收率研究

低矿化度水驱作为应用于低渗油藏、煤层气储层及常规水驱特高含水期的一项提高采收率技术,在行业内已形成共识。但目前对于低矿化度水驱提高采收率的研究有限,且仅限于低渗、特低渗油藏开发,更鲜有针对于水驱特高含水期~([1])。本文通过对注低矿化度水提高采收率机理的分析、并结合特高含水期储层特征的研究,得出了X油田水驱特高含水期利用现有井网条件和开发技术,注入低矿化度水挖潜剩余油、提高采收率切实可行的结论,同时提出矿场试验前需解决的主要问题,对国内老油田同时期接替技术的探索也具有重要借鉴意义。     

Optimal selection of representative samples for efficient digital camera-based spectra recovery

For digital camera-based spectra recovery, the spectral reflectance of the object being imaged always needs to be accurately recovered using training samples from available database. Considering the heavy workload when using all samples in database as training samples in practice, a new representative samples selection method is proposed for efficient digital camera-based spectra recovery based on single RGB image. The representative simulation system is firstly constructed through correlation analysis of spectra recovery results of different systems, and based on the representative simulation system, a few number of representative samples are selected from the database based on minimum of the defined simulate spectra recovery error. The effectiveness of the proposed method is evaluated and compared with existing method. As the results show, the proposed method outperforms the existing methods, and the robustness of the selected representative samples is consistent with the database in practical applications.     

Introduction of a generally applicable method to estimate retrieval of active molecules for similarity searching using fingerprints

Fingerprints are bit string representations of molecular structure and properties and are among the most widely used computational tools for similarity searching and database screening. Various fingerprint designs are available and their search performance is in general strongly dependent on the compound classes under study and the chemical characteristics of screening databases. Currently, it is not possible to predict the probability of identifying novel hits through fingerprint searching. However, for practical applications, such estimations would be very useful because one might be able, for example, to prioritize fingerprints and compound selection strategies or decide whether or not a similarity search campaign with subsequent experimental evaluation of candidate compounds would be promising at all. We have developed a method that makes it possible to predict the outcome of similarity search calculations using any type of keyed fingerprint. The methodology incorporates bit frequency distributions of reference molecules and the screening database into an information-theoretic function and determines the principally possible recall of active compounds within selection sets of varying size. We calibrate the function on diverse compound classes and accurately predict compound recovery in retrospective virtual screening trials. Furthermore, we correctly predict fingerprint search performance on two experimental high-throughput screening data sets (HTS). Our findings indicate that given a set of reference molecules, a fingerprint, and a screening database, we can readily estimate how likely it will be to retrieve active compounds, without knowledge about the distribution of potential hits in the database.     

Discovery of novel zeolites for natural gas purification through combined material screening and process optimization

An efficient computational screening approach is proposed to select the most cost‐effective materials and adsorption process conditions for CH₄/CO₂ separation. The method identifies eight novel zeolites for removing CO₂ from natural gas, coalbed methane, shale gas, enhanced oil recovery gas, biogas, and landfill gas sources. The separation cost is minimized through hierarchical material screening combined with rigorous process modeling and optimization. Minimum purity and recovery constraints of 97 and 95%, respectively, are introduced to meet natural gas pipeline specifications and minimize losses. The top zeolite, WEI, can recover methane as economically as $0.15/MMBTU from natural gas with 5% CO₂ to $1.44/MMBTU from natural gas with 50% CO₂, showing the potential for developing natural gas reservoirs with higher CO₂ content. The necessity of a combined material selection and process optimization approach is demonstrated by the lack of clear correlation between cost and material‐centric metrics such as adsorption selectivity. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1767–1785, 2014     

微波辐射法氢交换Naβ分子筛催化合成蒽醌及其分离

用微波辐射法对Naβ分子筛进行氢交换,并对微波辐射条件进行了优化.通过对微波辐射法与常规加热方法氢交换Naβ分子筛的催化性能比较,发现利用微波辐射法省时,节能,高效.用溶剂法对产物进行了分离,通过对不同溶剂的筛选,发现N,N-二甲基甲酰胺是较合适的溶剂,分离得到蒽醌的纯度为97.98%,回收率为93.90%.     

注水利用率方法评价油藏开发效果

本文通过注水利用率方法对水驱砂岩油田进行水驱效果评价。以阶段存水率为基础,引入了无因次注入曲线和无因次采出曲线,回归出不同水驱采收率条件下,阶段存水率与采出程度关系式,并绘制成了二者关系标准图版,利用该图版可对开发调整效果进行评价。     

变压吸附的实质

变压吸附是利用分子筛筛分机理的特性来实现气体分离的。由于分子运动自由程的不同,气体分子通过分子筛的孔向孔内扩散时所受阻力不同,导致在孔内扩散速率不同,宏观上这种分离体现为气体被固定于分子筛的孔内部被"吸附"。实际操作时,不断采取"加压吸附-减压脱附"循环方式,因此被形象地称为"变压吸附",其实质是基于分子筛孔本身的筛分机理,并非吸附机理。通过变压吸附的机理分析,我们确定了分子筛孔径的选择方法,同时分析了变压吸附过程的影响因素。     

Development of a data‐driven fuzzy screening model for enhanced oil recovery methods using an adaptive weighting system

Screening of enhanced oil recovery (EOR) methods is a main prerequisite for EOR planning and design. In this study, an integrated data‐driven screening model (DDSM) is developed to improve EOR screening using the combined capabilities of the fuzzy expert approach (FEA) and support vector regression (SVR) techniques. In this study, EOR field data from the past 40 years were reviewed to generate an updated and reliable EOR criteria table as a basis to construct a fuzzy screening model. The DDSM was evaluated to determine the quantitative screening and ranking of EOR methods using seven field datasets, including the fast forecasting of the nominated EOR methods. In order to improve screening performance, a fuzzy model was integrated using 4 SVR models to predict the adaptive weights of the screening parameter for decision making. The SVR models can predict the recovery factor (RF) of EOR methods including gas, chemical, steam, and combustion to calculate the adaptive effective weight of the screening parameters. The SVR models were trained with datasets generated from simulations of the EOR process. The absolute average error (AAE) of the SVR models from the simulation varied within the range of 0.078–0.095 for the prediction of the RF. The DDSM results were compatible to the data published in other literature. In addition, the developed model can provide comparable results to common screening software. The results showed improvements due to the adaptive weighting system on the EOR methods’ screening for the studied reservoirs relative to the fuzzy engine with constant weights. The presented integrated model can guide the screening process to select the efficient EOR method in practical applications.     

Optimization of Alkali,Switchgrass, and Extruder Parameters for Maximum Sugar Recovery

The US Department of Energy wants to replace 30 % of transportation fossil fuel with biofuel by 2025. A viable biomass pretreatment method might be found through extrusion. Extrusion pretreatments show a significant improvement on sugar recovery from different biomass feedstocks. However, glucose and combined sugar recovery from extrusion pretreated switchgrass was less than 50 %. Extrusion combined with other pretreatment methods could improve sugar recovery from switchgrass. Low‐concentration alkali acts as delignification agent without degrading the carbohydrates. In order to evaluate the combined effect of alkali soaking and extrusion, switchgrass samples of different particle sizes were soaked at different alkali concentrations for 30 min at room temperature and then extruded, using a lab‐scale single screw extruder at various barrel temperatures and screw speeds. Statistical analyses confirmed that all the independent variables considered had significant effect on sugar recoveries. The optimum pretreatment conditions resulted in a maximum combined sugar recovery of 88 %.     

Using weighted pseudo‐inverse method for reconstruction of reflectance spectra and analyzing the dataset in terms of normality

Most of spectral estimation methods are based on improving the learning‐based procedures which mainly modify the training sets used by the basic methods. In this article, a new method is developed for analyzing of superiority of these modified processes to the basic methods in terms of normality of datasets. Hence, two qualitative terms, named generality and similarity are introduced to interpret the recovery achievements of different databases and their roles as training and testing sets. Also, a simple technique based on dataset modification of pseudo‐inverse method is introduced for the recovery of reflectance spectra of samples from their corresponding colorimetric data. The method modifies the training dataset according to the color specifications of test sample. In fact, different weighting matrices are employed as dynamic modifiers to improve the pseudo‐inverse estimation as a simple recovery method. The employed datasets are examined in the self as well as cross test conditions and the results are spectrally and colorimetrically evaluated. The root mean square errors between the reconstructed and actual spectra along with the corresponding color difference values under different illuminants decrease by employing the suggested modification method in comparison to classical pseudo‐inverse technique as well as the recently improved version named optimized adaptive Wiener method. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010     

冷却塔动能回收风筒的流态分析研究

大型机力抽风冷却塔的轴流风机具有大风量低压头特性,出口动压约占风机全压的30%～40%,通过模拟动能回收风筒的试验,观察到风筒出口气流流速分布的不均匀性,当扩压筒的型线不同时,出口流速分布的不均匀性有别,因此在计算扩压筒出口的动压时,应根据不同扩压筒型线采用不同的不均匀系数给予修正。扩压筒的阻力系数的求取的方法应进一步完善,即根据扩压筒的不同型线,建立扩压筒的筒高与直径比和风筒内风速不均匀系数的关系曲线查取不均匀系数。