现场水分析技术及其在东方气田高温高压气井中的应用

在高温高压气井钻井作业中,钻井液体系调整较频繁且调整范围大、侵入地层较深,导致电缆测试样品的流体性质和侵入地层的钻井液滤液组成比例难以准确判断,为此探索了一种新的现场水分析技术,并在莺歌海盆地东方气田高温高压气井中取得了良好的应用效果。应用本文提出的现场水分析技术,可以快速准确地定量分析电缆测试储层流体中的钻井液滤液和地层水的组成比例,计算储层中流体的总矿化度,进而有助于定性识别流体性质,指导现场测试取样作业,为作业者提供快捷的决策依据。

可动水分析技术在文33沙三上低阻油层评价中的应用

文33块沙三上为高压低渗油藏,储层岩性细、地层水矿化度高以及油藏高度低的特点决定常规的低阻油层评价方法不适用该地区。针对油藏特点,提出了可动水分析技术,分析了产层含水饱和度与束缚水饱和度之间的关系,确定出可动水饱和度定量评价低阻油层,并揭示该区域低阻油层的分布特征。利用该技术对文33块沙三上可能产生低阻油层的井进行处理解释,26个层补孔得到证实,累计增油1.5×10~4t,取得了显著的应用效果。

水分析技术在古潜山探井的应用

水分析技术是古潜山钻探实施欠平衡录井的一项配套技术,应用现场水分析中所测定的主要离子含量变化规律,来判断地层的油水、气水界面,通过古潜山12口井水分析资料的研究应用,在判断油水界面方面取得了很好的效果,这种技术在现场随钻过程中能快速、准确地判断出油水、气水界面。

基于电缆地层测试取样的水分析技术及泵抽时间优化

电缆地层测试作业因钻井液侵入、储层渗透性、泵抽效率等因素影响,经常不能取到较纯净的原状地层流体样品,导致储层流体性质判断困难。在传统的现场快速水分析技术基础上,此文提出利用甲酸根作为特征离子来计算样品的纯度,判别取样样品的流体性质。与此同时,提出采用电阻率计算方法,求取样品纯度与电阻率变化率的关系,进而提出电缆地层测试取样的最佳时间节点。海上数十口井实际应用表明,该技术不仅可为现场作业决策提供重要的依据,也可大大节约勘探成本,降低作业风险。

水环境监测技术与监测质量控制要点研究

水环境监测在保障水资源安全和保护生态环境中起着非常重要的作用。社会经济的快速发展和工业化进程的加快,水体污染问题日益严重,对水环境监测的需求也在增加。为了提高监测结果的准确性和代表性,必须建立一套系统的质量控制体系。在水环境监测技术分析中,除了传统的监测方法外,新兴的技术手段也为数据采集和处理提供了更多选择,但如何在各种技术和方法中保持监测质量的高度一致性,仍然是一个亟待解决的课题。本文通过分析水环境污染的定义与分类,研究了水环境监测技术,最后探讨了水环境监测质量控制要点。

博太科HYGROPHIL F光纤技术微量水分析仪

博太科（BARTEC）HYGROPHILF系列微量水分分析仪采用专利技术，根据水分遇到光谱会使光的波长发生变化，该变化反应出水分的含量，利用该原理来测量水分含量、露点、相对湿度、蒸汽压力等相关参数。

深水工程勘察技术研究现状与展望

对国内外深水工程勘察相关技术,如:水下声学定位、海底浅层声探测、潜器勘测、深水海底浅表层取样与原位测试、深水钻孔取样(心)与原位测试以及深水地质灾害综合分析与评价等技术的研究现状进行了综述,并对其未来发展方向做了探讨和展望。本文成果对于积极发展具有自主知识产权的深水勘察工程技术与装备,更好地服务我国深水油气勘探开发工程具有重要参考价值。

一种定量判别储层流体性质的新方法

在录井技术及常规测井难以有效确定储层的流体性质时,基于电缆测压取样,在地面进行油水样分离后,采用现场水分析技术和现场原油高温高压物性分析技术,可以快速有效地解决该难题。对于水样,利用现场水分析技术可以确定其离子组成、总矿化度以及泥浆滤液与地层水的体积,再根据图版法,可以计算出地层水在地层条件下的体积。对于油样,利用现场原油高温高压分析技术,可以确定原油的黏度、体积系数等高压物性参数,并计算出原油在地层条件下的体积。根据取样在地层条件下原油与地层水的比例,即可定量地确定储层的流体性质。该判别结果较目前测井解释结论进一步定量化,且可有效确定储层,特别是油水同层的含水比例或产水率,有效指导油田的勘探开发作业。

基于电缆地层取样的气藏流体定量判别新方法

勘探阶段精确定量计算储层流体性质的方法主要是钻杆中途测试技术(DST),但海上DST评价费用较高。为此,提出利用电缆地层取样技术,将取到的地层流体样品在地面条件下进行气液分离,记录气体和液体样品的体积;利用现场水样分析技术,快速有效地确定液体样品中的各离子浓度,判断样品中泥浆滤液与地层水的体积比例;根据体积系数计算模型,将气体和地层水在常压下的体积折算到地层条件下的体积,得到地层条件下的气水比例,即定量地确定储层的流体性质。该方法进一步量化了测井解释结论,特别是气水同层,得到了地层产水率等参数,有效指导了油田的勘探开发作业。

Analysis and innovation of key technologies for autonomous underwater vehicles

As the mission needs of the autonomous underwater vehicles(AUV) have become increasingly varied and complex,the AUVs are developing in the direction of systematism, multifunction, and clustering technology, which promotes the progress of key technologies and proposes a series of technical problems. Therefore, it is necessary to make systemic analysis and in-depth study for the progress of AUV's key technologies and innovative applications. The multi-functional mission needs and its key technologies involved in complex sea conditions are pointed out through analyzing the domestic and foreign technical programs, functional characteristics and future development plans. Furthermore, the overall design of a multi-moving state AUV is proposed. Then, technical innovations of the key technologies, such as thrust vector, propeller design, kinematics and dynamics, navigation control, and ambient flow field characteristics, are made, combining with the structural characteristics and motion characteristics of the new multi-moving state AUV. The results verify the good performance of the multi-moving state AUV and provide a theoretical guidance and technical support for the design of new AUV in real complex sea conditions.

Thermal Dehydration Kinetics of Gypsum and Borogypsum under Non-isothermal Conditions

Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.

Economic and Technical Analysis of a Reverse-Osmosis Water Desalination Plant Using DEEP-3.2 Software

Reverse osmosis （RO） is proved to be the most reliable, cost effective, and energy efficient in producing fresh water compared to other desalination technologies. It is the fastest-growing desalination technology with a greater number of installations around the world. The economic and technical performance of a medium-capacity RO desalination plant （2,000 m^3/day） proposed to be installed in Umm Qasr city south of Basra, Iraq is analyzed using DEEP-3.2 software created by the International Atomic Energy Agency （IAEA）. This port city is located on the Gulf shore and does not have any fresh water resources. The analysis shows that the cost of fresh water produced by this plant is US$0.986/m^3 with a good quality of fresh water （279 ppm）, which is a reasonable price for this remote area. The analysis also shows an increase in water production cost of about 12% at increased electricity price from 0.06 to 0.1 US$/kWh, 53% when the seawater salinity increased from 35,000 to 45,000 ppm, 2.5% when the seawater temperature decreased from 33 ℃ to 20 ℃, and 0.71% when the interest rate increased from 0% to 5%. Pumping fresh water from the Basra purification plant （located 175 km north of Umm Qasr） is 22.16 times the cost and 236.7% poorer quality than the fresh water produced by the RO plant.

Retrieval of Total Suspended Matters Using Field Spectral Data in Shitoukoumen Reservoir,Jilin Province,Northeast China

From August to October in 2006,three times of field spectral measurements with a Field Spec FR spectroradiometer(Analytical Spectral Devices,Inc.,USA) were carried out in Shitoukoumen Reservoir,Jilin Province,Northeast China. Owing to the serious soil and water loss in the upstream,reflectance curves of the reservoir were characterized by high concentrations of total suspended matter(TSM) . Extending the spectral analysis to 1200nm in the near-infrared band,this research revealed an obvious reflectance peak around 1070nm which was caused by the strong backscattering of high TSM. The method of partial least squares(PLS) regression was applied to retrieving the TSM. Reflectance in two spectral bands,i.e.,675-948nm and 1029-1105nm,were used as variables to develop PLS models. Traditional linear regression,first derivative model and logarithmic model were also used for the comparison of different models. Results showed that the PLS model based on Rrs(675) -Rrs(948) gave out best results with high precision and stability. Although the PLS model based on Rrs(1029) -Rrs(1105) did not have an outstanding performance due to lots of noise,the reflectance peak in the near-infrared band was an important TSM feature and its efficient exploitation would have a considerable significance in TSM remote sensing.

Influence of mining thickness to the mechanical characteristics of gateways at FMTC faces

To make a better understanding of the mechanical characteristics of the surrounding rocks in the tailentry and headentry with different coal seam thickness at fully mechanized top-coal caving face （FMTC face）, the stress transition and displacement around the periphery of the gateways with different coal thicknesses were investigated in details by means of in situ measurement and 3-D numerical simulation. The research shows that the stresses decrease in the two spallings of the headentry and floor at goal with the increase in mining thickness. The roof pressure in the gates does not change obviously with the coal thickness, but the thicker the coal seam is, the farther the maximum stress will apply to the coal rib at the working face. The vertical stress is higher than the horizontal stress at two spallings of the gate, while its horizontal stress is higher than the vertical stress at the roof. The relative displacement between the roof and floor and the two spallings in the gateways increases gradually with the increase in coal seam thickness in a definite range in front of the face. Near the mining face, the stress decreases in the surrounding rock of the gates, while the deformation appears the most intensive. It is proposed that the support concept to the tailentry and headentry should be changed from loading control to deformation control.

Application of multivariate statistical techniques in assessment of surface water quality in Second Songhua River basin,China

Multivariate statistical techniques,such as cluster analysis(CA),discriminant analysis(DA),principal component analysis(PCA) and factor analysis(FA),were applied to evaluate and interpret the surface water quality data sets of the Second Songhua River(SSHR) basin in China,obtained during two years(2012-2013) of monitoring of 10 physicochemical parameters at 15 different sites.The results showed that most of physicochemical parameters varied significantly among the sampling sites.Three significant groups,highly polluted(HP),moderately polluted(MP) and less polluted(LP),of sampling sites were obtained through Hierarchical agglomerative CA on the basis of similarity of water quality characteristics.DA identified p H,F,DO,NH3-N,COD and VPhs were the most important parameters contributing to spatial variations of surface water quality.However,DA did not give a considerable data reduction(40% reduction).PCA/FA resulted in three,three and four latent factors explaining 70%,62% and 71% of the total variance in water quality data sets of HP,MP and LP regions,respectively.FA revealed that the SSHR water chemistry was strongly affected by anthropogenic activities(point sources:industrial effluents and wastewater treatment plants;non-point sources:domestic sewage,livestock operations and agricultural activities) and natural processes(seasonal effect,and natural inputs).PCA/FA in the whole basin showed the best results for data reduction because it used only two parameters(about 80% reduction) as the most important parameters to explain 72% of the data variation.Thus,this work illustrated the utility of multivariate statistical techniques for analysis and interpretation of datasets and,in water quality assessment,identification of pollution sources/factors and understanding spatial variations in water quality for effective stream water quality management.

A Case Study on Construction Dewatering-lnduced Settlement Damage： Could This Have Been Avoided？

A homeowner reported extensive settlement damage approximately two weeks after the groundwater in the vicinity of the home was lowered at a nearby construction project. The infrastructure improvement project consisted of installing a 27-inch-diameter sanitary sewer main with an invert elevation about 19 ft below existing grade. Groundwater was lowered 12 ft during construction, down to a depth of 23 ft below existing grade. This paper addresses the following key questions regarding settlement and potential structural damage as a result of a temporary drop in groundwater caused by construction dewatering： （1） How could a decrease in groundwater elevation cause settlement？ （2） Is this a highly unusual or atypical phenomenon that cannot be explained or estimated using science and engineering techniques available to the engineering profession？ （3） Based on the standard of care at the time, should these problems have been anticipated, or at least examined, by the engineering firms engaged on this project？ Answers to these questions are addressed herein using results from geotechnical analyses and data obtained from laboratory and in-situ tests.

Feasibility analysis for monitoring fatigue crack in hydraulic turbine blades using acoustic emission technique

In order to investigate the feasibility of monitoring the fatigue cracks in turbine blades using acoustic emission (AE) technique, the AE characteristics of fatigue crack growth were studied in the laboratory. And the characteristics were compared with those of background noise received from a real hydraulic turbine unit. It is found that the AE parameters such as the energy and duration can qualitatively describe the fatigue state of the blades. The correlations of crack propagation rates and acoustic emission count rates vs stress intensity factor (SIF) range are also obtained. At the same time, for the specimens of 20SiMn under the given testing conditions, it is noted that the rise time and duration of events emitted from the fatigue process are lower than those from the background noise; amplitude range is 49-74 dB, which is lower than that of the noise (90-99 dB); frequency range of main energy of crack signals is higher than 60 kHz while that in the noise is lower than 55 kHz. Thus, it is possible to extract the useful crack signals from the noise through appropriate signal processing methods and to represent the crack status of blade materials by AE parameters. As a result, it is feasible to monitor the safety of runners using AE technique.

Hydro-hypsometric analysis of tropical river basins,Southwest Coast of India using geospatial technology

The key aspect in planning and management of water resources is to analyze the runoff potential and erosion status of the river basin.For the detailed investigation of hydrological response freely available Cartosat-1(IRS-P5) data was used for the preparation of digital elevation model(DEM).The runoff potential and type of erosive process of 22 river basins originating in the global biodiversity hotspot of Western Ghats,was inferred through hypsometric analysis.Several parameters like Hypsometric integral(HI),maximum concavity(Eh),coordinates of slope inflection point(I) given by a* and h* and normalized height of hypsometric curve(h) were extracted from the hypsometric curves and used for understanding the hydrological responses.From the hypsometric curves,the landform evolution processes were inferred.Contribution of diffusive and fluvial processes in slope degradation of the river basins was understood.Basins with lesser area(<100 km^2) were found to have a positive correlation between hypsometric integral and basin area,whereas for large basins no such correlation exists.Based on the study,river basins can be prioritized for the appropriate conservation measures.

A techno-economic analysis of aquaculture business in Ogun State,Nigeria

Fish supplies 25% of the total protein source in developing countries. A techno-economic analysis was performed for developing a good business proposal for aquaculture loans to enhance aquaculture development in Nigeria. A case study of catfish Clarias gariepinus framing was conducted in Abeokuta North Local Government of Ogun State, Nigeria. The results show that the fixed cost is N18 338 per year, and the variable cost is N459 700 per year, accounting for the largest amount of the total; therefore, a profit of N43 289 per month can be made. Sensitivity analysis was performed to assess any risk(s) that associated with unfavorable changes in government policy with particular reference to monetary policy. Positive net present value shows that the investment in fish farm is economically feasible and the net investment ratio is 3.52. Also, the benefit-cost ratio is 2.17. The internal rate of return (IRR) is 21% showing that the enterprise is able to offset the interest being charged on the loan. It is therefore worthwhile to invest into fish farm business in the study area. The study suggests that to better sustain the local aquaculture business, the government should create a good conducive environment to foster development of the fish farming. Government intervention is urgently needed to solve problems such as in traditional land tenure, grant credit facilities and subsidies, to enhance the aquacultural development in the country.