Abstract:Artificial shale sample preparation method in shale stability index(SSI) evaluation test was improved.With shale powder in B28 well,the optimum preparation condition of shale sample in SSI test was obtained.The slug was suppressed under 10.5 MPa to get shale sample with 14.03% water content which simulated the formation of high water content,and dry shale powder was suppressed under 10.5 MPa to get shale sample with 1.91% water content which simulated rock samples with low moisture content of deep formation.The optimum experiment conditions of SSI test was established: immersing in test solution at 65 ℃ for 8 h and then measuring SSI value of the shale sample.The results of scanning electron microscopy(SEM) micro-structural analysis showed that the micro-pore scales of shale samples in the two preparation method were similar to that of actual rock shale.Water content of high water content shale sample was similar to that of actual shallow shale formations which was of 12%—14%.Water content of low water content shale sample was similar to that of actual deep shale formations which was of 2%—3%.Relative error of the improved SSI evaluation method was of 2.91% which showed good parallel of the method.The improved method could effectively evaluate anti-collapse effects of anti-sloughing agents and anti-collapse systems and help understand mechanisms.

Abstract:Amphiphilic particles were firstly applied in the field of leak protection.Core-shell particles with hydrophobic polystyrene cores encapsulated by hydrophilic polyacrylamide shells were prepared via interface initiation polymerization.The polystyrene colloidal particles were prepared by using a concentrated emulsion as a precursor.The polyacrylamide shell was prepared via interface initiator constituted of oxidant,cumene hydroperoxide,reductant,and ferrous sulfate.The shape of amphiphilic particles was micro-spherical and there was slight adhesion between particles.The particle size in average was of 21.36 μm.The particles had good resistance of high temperature(180℃) in water-based slurry.The based slurry plugging with 1% amphiphilic particles had excellent plugging capability,which significantly improved with increasing amount of particles.It was found that with the increase in the amount of squeeze injection,extrusion injection pressure increased and reached the maximum of 14 MPa with 700 mL squeeze amount.The API filtration could be reduced by amphiphilic particles.The change of slurry rheology was little when the amount of particles was no more than 2%.Amphiphilic particles could be used for drilling and plugging at high temperature.

Abstract:To solve complicated downhole problems caused by wellbore instability,a thermally stable inhibitor YFF was developed,and the relative properties were investigated through inhibition test,plugging test,moreover,the effect of the field application of YFF was mentioned.The experiment results showed that YFF had positive charge and had a good inhibitory ability and plugging property.After adding 2% YFF,the cutting recovery increased from 35.3%(blank group) to 92.5%;while the expansion volume of 1% bentonite decreased form 92 mL(blank group) to 71 mL.The YFF had very good capacities of depressing the filter loss under high temperature of 200℃,however,which had little effects on rheological property of the drilling fluid.The plugging rate of the core was higher than 95% after treated by the polymer drilling fluid,4% bentonite+0.2% Na2CO3+0.2% flocculants KPAM+2%filtration reducing agent SPC+0.5%filtration reducing agent LV-CMC+3%filtration reducing agent SMP-1+2% plugging agent FT-1+1% filtration reducing agent SYP-1+3%YFF,moreover,the permeability restoration was high up to 95%.The field application indicated that YFF had good cooperation with the drilling fluids,as a result,wellbore stability and reservoir protection was realized by adding YFF.

Abstract:The law of stratigraphic physical and chemical properties of clay minerals distribution in Qingxi block was obtained by X-ray diffraction experiments,cuttings recovery rate and expansion ratio experiments,and the stratum clay mineral profile was built.Experiment results indicated that stratum clay minerals distributed as M shape,which need a strong inhibitory and sealing drilling fluid.It provided scientific basis for drilling fluid performance and maintenance in different sections.Aimed at the lithologic characteristics and drilling fluid technical difficulties in Qingxi block,the screening of inhibiter,fluid loss agent and high temperature stabilizer was done.The best formula of cationic drilling fluid with the strongest inhibitory and the highest sealing capability was established: 4% bent,0.4% K-HPAN,0.6% SMC,0.4% HS-1,0.3% CHM,0.3% NW-1,2% SMP,2% PSC,4% SPNH.After the application in more than 30 wells on site,the complex accidents in down hole greatly reduced and drilling cycle obviously shortened.The complex loss rate decreased from 4.50% to 1.62%,average rate of penetration enhanced by 26.88% and drilling cycle shortened by 40.5%.This drilling fluid could be easily maintained and operated which met the requirement of safe and fast drilling.

Abstract:The polyampholyte,ampholytic polyphenylene sulfide were prepared via sulfonation reaction,bromination reaction and substitution reaction between bromide and quaternary ammonium group or tertiary amine group.The degree of sulfonation and the contents of bromide were investigated by acid base titration and Mohr method,respectively,and the structure of these polymers was characterized by IR and UV-vis measurement.The results indicated that sulfonation degree of polyphenylene sulfide could be up to 47.6% under the best conditions,i.e.,the ratio of oleum to PPS was 1∶ 15(g/mL),reaction temperature was 105℃ and reaction time was 4 h.The content of bromide was 28.20% when the dosage of FeCl3 was 4%,the reaction time was 4 h,and the reaction temperature was 40℃.Bromine on the benzene ring was substituted by quaternary ammonium group and tertiary amine group.Through analysis of IR and UV-vis spectrum,it could be speculated that the modification of polyphenylene sulfide was successful and the polyampholyte was obtained.

Abstract:An extracellular polysaccharide(EPS) producing bacteria,named BIT-BP004,was isolated from oil/water sample of Liaohe oilfield.The optimal medium compositions in shake scale for strain BIT-BP004 were determined as follows: sucrose 7.5 g/L,NaNO3 0.5 g/L,K2HPO4 1.5 g/L,KH2PO4 3 g/L,MgSO4 0.1 g/L,CaCl2 0.01 g/L,initial pH 6 and inoculant’s volume 1%.The EPS yield was 4.11 g/L in batch culture after 24 h.By orthogonal design,the factors of temperature,mineral salt concentration and pH value were selected to assay the physico-chemical property of fermentation.The results showed that experiment factors had a larger effect on viscosity of fermentation,and the affection capacity was arranged as follows,temperature > mineral salt concentration > pH,indicating that temperature was a decisive factor on the viscosity of the fermentation broth.

Abstract:A delayed gelating silicate-based plugging agent was developed by sodium silicate,methyl sodium silicate,phosphoric acid and slow-release acid(A acid) with oilfield wastewater for high permeability oilfield in Gudao.Effects of each composition’s proportion on the performance of plugging agent were investigated under atmospheric pressure and 60℃ which simulated the temperature of formation.It was shown that methyl sodium silicate improved the performance of silicic acid gel,such as the strength and elastic properties.A acid released H+ slowly to achieve the objective of delayed gel forming.The gelation time decreased with increasing amounts of sodium silicate and A acid,and increased with increasing amount of methyl sodium silicate.The maximum value obtained when the dosage of phosphoric acid was of 0.3 mL.While the total volume of plugging agent was of 100 mL mixed with 10 mL sodium silicate,5 mL methyl sodium silicate,0.3 mL phosphoric acid,20 mL A acid and 64.7 mL oilfield wastewater,the gel with good strength formed and the longest gelation time was of 13.5 hrs.

Abstract:There existed many problems,such as high pressure of water injection wells,low water absorption index,slow effect block injection,water imbalance,etc,during surface water injection process in the eighth reservoir of Jiyuan oilfield.On basis of the analysis of the injective water and formation water quality,the compatibility of the injective water and formation water was studied by the scaling prediction and laboratory simulation method.The experimental results showed that the formation water was CaCl2 type,and the injective water was Na2SO4 type in Jiyuan oilfield.When mixing the formation water and the injective water in different proportions,there was not scale to form at 30℃,whereas,calcium carbonate scale deposits occurred at 80℃(formation temperature).The scaling prediction results showed that the calcium carbonate scale did not occur at 30℃,meanwhile,with the increase of the proportion of formation water,calcium carbonate scaling tendency increased at 50℃.When the ratio of the formation water and injection water was 4∶ 6—10∶ 0,calcium carbonate scale deposit would form at 50℃.Furthermore,the calcium carbonate scale tendency increased at 80℃,scale deposite occurred in any proportion of the formation water to injection water.The IS scaling prediction results showed that calcium sulfate scale did not occur when the formation water and the injective water mixed at any ratio at 30—80℃.All mentioned above showed that the poor compatibility and the scale of injected water and formation water was the main reasons caused high pressure of water injection wells in the eighth reservoir of Jiyuan oilfield.

Abstract:In order to meet the practical demand of the field,with the means of the instrumental analysis,physics modeling and the reservoir engineering theory,the viscosity and molecular coil dimension of the compound polymer,obtained by mixing the polymers with different molecular weight of 1400×104,1900×104 and 2500×104,named as "middle molecular","high molecular" and "ultra-high molecular",and the oil displacement efficiency were investigated,in addition,the EOR mechanism of the compound polymer was also presented.The results showed that with the proportion of the "ultra-high molecular" polymer increasing,the molecular coil dimension and the viscosity of the compound polymer increased.Compared to the "high molecular" polymer,the molecular coil dimension of the compound polymer was broader and the abilities of salinity resistance and shearing resistance was stronger.The physics model experiment indicated that as far as the polymer solution with the same viscosity as was considered,the oil displacement efficiency of the compound polymer solution was better than that of "high molecular" polymer.The enhancement of oil recovery increased with the proportion of the "ultra-high molecular" polymer increasing.

Abstract:The core experiment results of 1-D physical modeling and 3-D physical modeling showed that the combined flooding of microgel slug with polymer slug had a good positive composite effect.The function of microgel slug and polymer slug was to plug the high permeable channel and increase the sweep efficiency.The function of polymer slug and microgel slug was to prevent the breakthrough of post-water flooding and increase the effective time of polymer slug.The function of polymer slug was to reduce water-oil mobility ratio and increase the displacement ability.So the recovery of combined flooding was higher than the microgel flooding and polymer flooding.The combined flooding(0.19 PV microgel slug+0.32 PV polymer slug) was applied in zone 437Ⅱ1-2 of Henan oilfield.By the end of 2007,the incremental oil amount of one ton polymer was of 105 t and the oil recovery was enhanced by 7.44%,higher 3.14 percent than the polymer flooding.Furthermore,the chemical cost of combined flooding was decreased by 11.4% compared with polymer flooding.

Abstract:In this paper,the properties and the influencing factors of the foam,formed by amphiphilic polymers,were studied.The results showed that the volume of amphiphilic polymer foam were smaller in contrast to that of the ordinary surfactant foam,furthermore,the stability of amphiphilic polymer foam was much better than the latter.The foam properties varied with the concentration of amphiphilic polymer,and the foam performance of type I amphiphilic polymer would be best at the concentration of 1.5 g / L,which had good heat-resistance and salt-tolerance.However,the foam performance would become worse under high shearing(the rotation speed >4000 r/min) or when the content of kerosene exceeded 20%.

Abstract:The influence of the wettability alteration caused by cationic surfactant(GS12-2-12) on the oil displacement efficiency of the sand core was investigated in this paper.The results showed that both the hydrophobic and hydrophilic surface of the sand core would change to mid-wetting when displaced by GS12-2-12 aqueous solution,as a result,the dynamic adsorption of GS12-2-12 of 0.3—0.7 mg/g on the surface of the core was established,and the change of the contact angle was 50°to the most.During this process,the adhesion work between the crude oil and the surface of the core also descended,which would weaken the Jamin effect of the pore and reduce the resistance to motion of oil and water,resulting in enhancement of the oil recovery by 5%.The stripping oil film on the surface of the sandstone was observed by microscopic displacement test on photoengraving model,which displaced the remaining oil being difficult to be displaced by water flooding.

Abstract:The dynamic interfacial tension of oil-water and the displacement effect of anion Gemini surfactants GA12-4-12 and dodecyl sulfate sodium were contrasted,and the displacement effect of the compound of GA12-4-12 and non-ionic surfactant ANT1,ANT2 was investigated in different permeability and salinity condition.The results showed that GA12-4-12 possessed superior interfacial activity and ability to enhance the oil recovery,especially when the concentration of CA12-4-12 was 800 mg/L,the enhancement of oil recovery was 11.67% based on 63.38% of water flooding.GA12-4-12 was suitable for medium and low permeability reservoirs,however,the ability to enhance the oil recovery gradually declined with increasing salinity.Compound oil displacement experiments showed that in 2.5 ×105 mg/L salinity conditions,the oil recovery of low permeability cores of 48.3×10-3 μm2 was enhanced by the SP1 system(400 mg/L GA12-4-12+100 mg/L ANT1) for 10.67% based on 60% of water flooding;in 5×104 mg/L salinity conditions,the oil recovery of middle-low permeability cores of 417×10-3 μm2 was enhanced by the SP2 system(400 mg/L GA12-4-12+100 mg/L ANT2)for 8.42% based on 57.89% of water flooding.

Abstract:The surfactant assisted steam flooding efficiency was systematically investigated by means of laboratory experiments and numerical simulation in light of the specific reservoir conditions of Shengli oilfield.Some property parameters of high-temperature surfactant(WT) such as interfacial tension,temperature resistance and viscosity reducing property were determined.Experiment results showed that the minimum dynamic interfacial tension between WT solution and oil was of 10-2 mN/m.And the temperature resistance researched to 150℃.The half-life was over 15 d.When the mass ratio of oil to water was of 8∶ 2 and 7∶ 3,the viscosity reducing rate was higher than 86% and 95%,respectively.The ultimate recovery of surfactant assisted steam flooding was of 74.32%,which improved by 12.11% comparing with steam flooding.Based on displacement experiments,the injection parameters of surfactant for the typical well group in Zhongerbei Ng5 of Gudao oilfield were optimized by numerical simulation technique.The optimum injection project was obtained as follows: alternative injection,0.5% surfactant dosage and 0.3 PV injection volume.The increasing oil recovery of the optimum plan predicted was of 3.58%.The expression of economic minimum oil increment was derived by dynamic economic evaluation.Based on this,a method for studying economic and technical boundary values of surfactant assisted steam flooding was built.Effective thickness and oil viscosity economic and technical boundary values of the typical well group were studied.

Abstract:According to the requirement of high-temperature low permeability reservoir hydraulic fracturing treatment to the propriety of fracturing fluid,a novel high temperature polymer was synthesized by polyacrylic acid,polyacrylamide,2-acrylamido-2-methylpropanesulfonic acid(AMPS).Performance evaluation experiment results showed that the viscosity of fracturing fluid decreased by 1.4 mPa · s after shearing 3 hrs,which possessed good shear stability and viscosity recovery propriety.The crosslinking time gradually decreased with increasing temperature.The temperature resistance of fracturing fluid reached to 170℃.The fracturing fluid was difficult to break at 60℃,which could be overcome through increasing the dosage of gel breaker.The residue of polymer fracturing fluid was of 0.83%,and the damage to core matrix was only 16.7%.The damage to propped fracture was far less than guar gum fracturing fluid which was fit for the stimulation of high-temperature low permeability reservoir.

Abstract:The task of how to improve flow back ratio,decrease the formation damage caused by fracturing liquid,and achieve high flow conductivity of artificial fracture had already become a vital question for the reservoir stimulation technology.Through the physical and chemical behavior analysis of nitrogen and carbon dioxide,their cleanup mechanism was researched,the flowing-back model of accompanying gas was built,and the design software of accompanying gas was drawn up.Associating with oilfield examples,the affecting elements of accompanying gas were researched,meanwhile the parameters of flowing back technology were optimized.The results showed that when the well depth and pump injection increased or start-up pressure gradient decreased,the companion ratio and the companion displacement of liquid nitrogen injection increased.The companion ratio of liquid nitrogen injection increased about 0.3% as the well depth increasing per 100 meters,and that decreased about 0.6% as the start-up pressure gradient increasing per 0.01 MPa/m.The change rate of bottom pressure was the same as that of head pressure in a well.The bottom pressure of a well increased about 5 MPa when the wellhead pressure increased 5 MPa.With increasing injection rate,the pressure of the well bore decreased.The bottom pressure of a well decreased about 1.75 MPa when the injection rate increased 0.5 m3/min.When the mathematic model was applied in Shengli oilfield,the fracturing liquid flow back rate achieved 90%,and the fracturing well production increased by 2.7 times.Field application showed that the mathematic model worked reasonably,and accounting parameters were accurate and reliable which could be used to guide field construction.

Abstract:The decrease of gellant concentration would make the proppant carrying capacity of fracturing fluid become poor.Adding fiber in base fluid could reduce the concentration of gellant under the premise of ensuring the proppant pack stability.The effects of fiber to proppant pack stability were evaluated.Experiment results showed that the settling velocity of proppant decreased with increasing quantity and length of fiber.Fiber XW-3 with content of 0.2% and length of 8 mm could improve the proppant carrying capacity of fracturing fluid.And the addition of fiber was no influence on the temperature and shearing resistance to fracturing fluid.Rheological experiments showed that viscosity value increment reduced from 335.9 to 107.4 mPa · s when the dosage of fiber increased from 0 to 2.0%.Shear rate had smaller effect on the viscosity of fracturing fluid after adding fiber.Fracturing fluid containing fibers followed Kynch proppant sedimentation theory.The application of fracturing fluid in X well of Changqing oilfield on site indicated that fiber could improve the feasibility of fracturing fluid’s carrying capacity.

Abstract:Aimed at the shortcoming of the lower applicable temperature of the current domestic conventional organic boron crosslinker,an organic boron crosslinker DG-ZCY-15,which could be resistant to ultra high temperature of 180℃,was prepared by introducing high valence metal ions.The effects of the high metal content and alkali content on the heat resistance and gelling time of the fracturing fluid was investigated,as a result,the optimal formula of a fracturing fluid,possessing the advantage of heat resistance of 180℃and adjustable delayed crosslinking,was obtained as follows: 0.57% hydroxyl guar gum + 0.45%DG-ZCY-15+0.3% DG-10 temperature stabilizer + 0.3% alkali + 0.03% P-33 gel breaker + other.The performance of the fracturing fluid was evaluated and the application of the fracturing fluid in Dagong oilfield was introduced.The results showed that at the temperature of 180℃,the viscosity of the fracturing fluid was still above 50 mPa · s after being sheared for 120 min at the shear rate of 170 s-1,meeting the requirements of the sand fracturing construction in the super high temperature,super deep reservoir;the viscosity of the gel breaking liquid was only 1.45 mPa · s,and the surface tension of the gel breaking liquid was only 27.8 mN/m,moreover,the damage rate of the gel breaking liquid on the cores of 3 wells was below 20%.The fracturing fluid had been used in 50 wells,which the maximum botton temperature reached 189℃ in Dagang oilfield,the construction success rate being of 100%,hence,the satisfactory effects was achieved.

Abstract:The reactivity of mud acid and multi-hydrogen acid on the water-sensitive montmorillonite mineral was analyzed comparatively,and the dissolution rate and precipitation law of montmorillonite in the two acid systems were studied.At the same time,the concentration of Si4+,Al3+ in the residual acid was investigated.Microcosmic transformation in the structure of montmorillonite was observed by scanning electron microscopy(SEM).The experiment results showed that the dissolution rate of multi-hydrogen acid on montmorillonite was less than mud acid at 30℃ and 90℃.It would form secondary precipitates after the reaction of montmorillonite and mud acid at 90℃.When the multi-hydrogen acid reacted with montmorillonite,one aluminum-silicate-phosphonate plating formed over the surface of montmorillonite,which had low solubility in weak acids but could be rapidly dissolved by HCl.With increasing reaction time,the concentration of Si4+ in the residual acid increased at first and then decreased and that of Al3+ increased gradually after the reaction of mud acid and montmorillonite.Meanwhile,the concentration of Si4+,Al3+ in the residual acid both increased after the reaction of multi-hydrogen acid and montmorillonite.It indicated that the multi-hydrogen acid had a strong ability of absorbing and chelating to metallic ions.

Abstract:The acid filtration caused by wormhole was the significant factor which affected the design of acid fracturing and stimulation effects.And the investigation on the wormhole development was benefit for accurate calculation of acid filtration.The acid-rock reaction control experiments were carried out with 20% hydrochloric acid and gel acid,and the reaction rate and critical disk speed of two acid systems were compared.Based on the type of two different pores of porous and fracture in carbonate reservoir,different experiments were designed to study the acid filtration and wormhole development,which included artificial hole and artificial fracture made to simulate the flow characteristics in large pore and natural fractures.The results showed that the reaction rate of hydrochloric acid was faster than that of gel acid,and their critical rotation speed of mass transfer region and surface reaction control region were of 800 r/min and 600 r/min,respectively.Gel acid was benefit for wormhole extension due to slow reaction rate.Fractured carbonate reservoir had larger probability than porous carbonate reservoir to form wormhole.

Abstract:The effect of polymer on the interfacial activities of petroleum carboxylate was discussed by measuring the interfacial tensions between the crude oil of the fourth oil production plant of Daqing oilfield and petroleum carboxylate weak alkali(Na2CO3) / strong alkali(NaOH) solution with different surfactant concentration before and after adding polymer.The results showed that the interfacial tension between petroleum carboxylate∕Na2CO3 system and the crude oilcould reach ultra-low(10-3 mN/m) only when the concentration of Na2CO3 was 8—12 g/L.While the addition of the polymer could improved obviously the interfacial activities of petroleum carboxylate weak alkali(Na2CO3) system,especially in the region of relatively lower concentration of Na2CO3 and the region of relatively higher concentration of petroleum carboxylate.The interfacial tension of the system after adding polymer of 1500 mg/L reached ultra-low when the concentration of Na2CO3 was 4—12 g/L and the concentration of surfactant was relatively higher(0.8—3.2 g/L).The effect of polymer on the interfacial activities of the petroleum carboxylate/NaOH system was weaker than that of petroleum carboxylate/Na2CO3 system.When the concentration of NaOH was 4—6 g/L,the addition of polymer could improve slightly the interfacial activities of carboxylate/NaOH system,while the addition of polymer had opposite effect when the concentration of NaOH was higher(10—12 g/L).The mechanism of the effect of polymer on interfacial activities of petroleum carboxylate/alkaline system was probed from the point of view of chemistry.

Abstract:The erosion and dissolution of reservoir rock minerals by the alkali of ASP flooding made the sandstone passing into the reservoir fluid in soluble state,which caused severe scaling and blocking.Simulated the formation fluid,an experiment of Si2+\Ca2+\Mg2+\Ba2+ scaling was performed under 50℃.The results showed that the ASP-flooding-scale was mainly composed of carbonate and silicate.With increasing pH value of oil well producded liquid,the content of silicate in the scaling increased,while that of carbonate decreased.When the pH value was less than 10.7,the sedimentation velocity of silicates was higher,otherwise,it became lower.The different content of carbonate and silicate made the scaling state diverse.Flake silicate precipitation formed under low concentration of carbonate ion(80 mg/L),and granular carbonate precipitation formed under high concentration of carbonate ion(1100 mg/L).Silicon ion promoted the deposition of calcium.The maximum value of scale deposition(247 mg/L) was produced with silicon content 500 mg/L.The cation promoted the deposition of scaling,but Mg2+ wouldn’t take a precipitation reaction until Ca2+ and Ba2+ reached their chemical equilibrium.

Abstract:Polymer flooding produced water is hard to deal with because of the effect of the residual polymer(HPAM).A kind of efficient and compound flocculent was optimized and the degradation performance of different polymer degradation agent system was evaluated,the optimal concentration and ratio between flocculants and polymer degradation agent were determined through thermo-chemical sedimentation experiment.As a result,the optimal formulation of the treatment agent was obtained as follows: 100 mg/L poly aluminum ferric chloride +100 mg/L modified poly aluminium chloride +6 mg/L hydroquinone +8 mg/L K2S2O8+6 mg/L FeSO4.After treated,the oil content of the water of polymer flooding water decreased by 97.26%,the light transmission rate increased from 28.26% to 90.5%,and the viscosity of the water phase decreased from 1.8 mPa · s to 1.0 mPa · s,which reached the reinjection standard of oilfield.

Abstract:In this article,a new type PSAFMnS flocculant was synthesized by using Mn to modify PSAFS flocculant through compositing method.The effects of various factors on the performance of PSAFMnS flocculant during the preparation were tested and the structure of PSAFMnS flocculant was indicated by SEM.The optimized synthesis conditions of PSAFMnS flocculant was obtained as follows: ① the Si content,in term of the SiO2 content,≈ 2% and pH ≈ 5.0 for steady silica sol;② the molar ratio of Si,Al,Fe and Mn≈ 6∶ 8∶ 4∶ 3,pH ≈ 1.5,the temperature ≈ 25℃ and the reaction time ≈ 30 min.When the dosge of the PSAFMnS was 5 mg/L,the turbidity removal ratio of kaolin solution achieved 75%.The turbidity and oil removal abilities of PSAFMnS flocculants were obviously better than that of PSAFS flocculants,the turbidity removal ratio enhanced 17.96% based on 57.93% of PSAFS.

Abstract:The influence of three different surfactants(sorbitan(Z)-mono-9-octadecenoate Span 80,dialkenyl succinimide T152,multialkenyl succinimide T153) on the state of liquid membrane was studied by microscope.The effect of surfactant types on the particle size distribution of emulsion was analyzed by laser particle analyzer,and the pH value of the aqueous phase out of the W/O/W multiples emulsion film system was tested by pH meter.The results showed that,when the W/O/W multiple emulsion film were prepared under the conditions of 50 mL of the film solvent,2% of the carrier,2% of the atoleine,0.5 mol/L of the interior phase NaOH and 1∶ 6 of the emulsion water ratio.The pH value of the aqueous phase out of the emulsion film formed by Span 80 was the biggest and the film was damaged seriously,while the pH value formed by the T153 was smaller than others and the film was more stable.The mean grain size order of the aqueous dispersive phase in the W/O emulsion formed by the three surfactants was as follows: T153(60.369 μm)> T152(58.510 μm) >Span80(37.630 μm),moreover,the particle size distribution of the emulsion formed by T153 displayed the most intensively.When the emulsion/water ratio was 1∶ 5 and the initial sulfide content was 40 mg/L,the desulfuration efficiency of the W/O/W multiples emulsion film formed by T153 was the maximum,being of 98%.

Abstract:Three strins,named as NS-1,NS-3 and NS-5,which could degradate oil effectively,were isolated from the oil-polluted soil in Northern Region of Shaanxi and the degradation effect was determined by the method of colourimetry.The results showed that NS-1 could make the oil degrade by 89.63% when the original concentration of oil was 4 g/L.The culture medium of NS-1 was optimized by minitab software by the way of PB testing,Box-Behnken center combination design and the response surface analysis based on the fermentation medium.It was indicated that MgSO4,(NH4)2SO4 and NaCl were key factors for NS-1 growth,and the optimal recipe of the culture medium was 2.0% glucose,0.9% MgSO4,0.1%(NH4)2SO4,0.4% NaCl,and the yield of NS-1 was increased by 38.7% after culturing for 20 h,compared to that with LB culture medium.

Abstract:The current situation of CO2 displacing oil and CO2 sequestrated researches was reviewed.Nowadays,CO2 displacing oil had got good economic benefits outside and was carried out oil field experiment inside.And CO2 sequestrated researches were in exploring stage all over the world.The key problems in CO2 displacing oil and CO2 sequestrated researches contained five parts,such as enlarging sweep volume of EOR,carrier and medium choice of CO2 sequestrated,the formation damage in the process of CO2 displacing oil,air source,industrial coordination and overall planning.Finally,several development directions of CO2 displacing oil and CO2 sequestrated researches were proposed.

Abstract:On account of the steam overlap or fingering and low displacement efficiency in the conventional steam stimulation,recent developments of surfactant system assisted steam stimulation in heavy oil were presented,including steam/foam agent,steam/viscosity reducer and steam/cleanup agent.The recent studies,mechanism and application conditions for the three methods were summarized.Problems existed in various methods and their developing directions were pointed out.