Synthesis of temperature-resistant and salttolerant surfactant SDB-7 and its performance evaluation for Tahe Oilfield flooding (China)

In order to improve the enhanced oil recovery of high-temperature and high-salt oilfields, a novel temperature-resistant and salt-tolerant surfactant （denoted as SDB-7） was synthesized and evaluated for the Tahe Oilfield （Xinjiang, China）, which is representative of high-temperature and high-salt oilfields. It has a central reservoir temperature of 140 ℃ and salinity of 22.6× 10^4 mg/L. The temperature-resistant and salt-tolerant performance, interfacial activity, oil displacement efficiency, aging properties, and adsorption properties of the synthesized surfactant were evaluated for Tahe Oilfield flooding. The results showed that the SDB-7 was temperature-resistant and salt-tolerant capacity of 140 ℃ and 22.6×10^4 rag/ L, respectively, oil displacement efficiency under static condition of 84%, and adsorption loss of 0.4 mg/ g （less than 1 mg/g-oil sand）. In the heat aging experiment （under the temperature of 140 ℃ for 60 days）, the oil-water interracial tension and oil displacement efficiency of SDB-7 were almost unchanged. The oil displacement experiments showed that, under the temperature of 140 ℃ and the salinity of 22.6× 10^4 mg/L, the surfactant SDB-7 can enhance oil recovery by 14.5% after water flooding,suggesting that SDB-7 has a promising application in high temperature and high salinity （HT/HS） reservoir.

Rheological Properties of Hydrophobically Associating Polyacrylamide Solution

A temperature-resistant, salt-tolerant polyacrylamide, hydrophobically associating polymer （HAP）, was synthesized in the State Key Laboratory of Heavy Oil Processing. The rheological behavior of HAP solution was investigated by means of flow experiments in porous media and by using a HAAKE RS600 rheometer. The results of Nuclepore membrane filtration showed that filtration time increased sharply when the critical association concentration was reached. Shear rate had a greater impact on viscosity and shear stress with increasing HAP concentration. The HAP solution with a concentration of 100 mg/L （salinity 32,868 mg/L） exhibited negative thixotropy. However, at the same salinity the HAP solution showed thixotropy and its viscosity became greater when the polymer concentration increased to 1,500 mg/L. The flow experiments in cemented core samples indicated that the resistance factor and residual resistance factor of the HAP solution were 31.8 and 12 when polymer concentration and salinity were 1,500 mg/L, 32,868 mg/L at 85℃ respectively, which is favorable for flooding application. Such factors of partially hydrolyzed polyaerylamide 3530S were merely 3.14 and 1.71, so it could not be applied to polymer flooding in the oilfield with high temperature and high salinity.

Characteristics of Resistivity-temperature for Carbon Fiber Reinforced Concrete

The resistance response to temperature change of carbon fiber reinforced cement-based composites （CFRC） is reported, which shows some outstanding phenomena of positive temperature coefficient （PTC） of resistance and negative temperature coefftcient（NTC） of resistance during the temperature rising. The influences of carbon fiber, cement-based matrix and thermal cycles on the characteristics of temperatare-resistivity for the system were also discussed. Because of the special characteristics for temperature-resistivity, carbon fiber cement based composites can be useful in structure with the function of alarm for fire.

SYNTHESIS OF MELAMINE AND CASHEW NUT SHELL LIQUID MODIFIED PHENOLIC RESIN

Melamine,cashew nut shell liquid modifed phenolic resin is a kind of high temperature-resistance resin used in friction materials.This paper describes the resin formulation,synthesis,charac- teristic indexes,mechanical strenghth, infrared ray spectrum,TG,DTA,and discusses the sythetic way of resin modified result and the influence of catalyst on the reaction speed.

Preparation and Performance of HGM/PPENK-based High Temperature-resistant Thermal Insulating Coatings

Novel high temperature-resistant coatings with high mechanical strength and thermal-insulating performance were prepared with poly(ether nitrile ketone)(PPENK)resin as matrix and hollow glass microspheres(HGMs)as thermal-insulating filler.The corresponding mechanical and thermal-insulating study indicated that the mechanical properties of the coatings decreased with the increase of HGM content,and were improved after surface modification of HGM by KH570 resulting in enhancement of interaction between HGM and PPENK resin.The thermal conductivity of HGM/PPENK thermal-insulating coating decreased with the increase of HGM content and coating thickness,along with the decrease of the true density.It also showed slight increase trend due to HGMs surface modification.The HGM/PPENK coating filled with modified HGMs showed better thermal resistance than that of unmodified HGM/PPENK coating.The thermal decomposition temperature at 5%weight loss of the coating containing modified HGMs was 10°C lower than that of pure PPENK,and 40°C higher than that of neat HGM/PPENK coating.The coating exhibited commendable appearance after 400°C for 30 min.The merits of HGM/PPENK-based thermal coatings obviously demonstrated promising prospect in thermal protection fields.