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51.
52.
A study on the impedance responses of inhibitor desorption 总被引:1,自引:0,他引:1
王佳 《中国海洋湖沼学报》1998,16(1):54-59
INTRODUCTIONInhibit0rdesorptionfrequenhyresultSininstabilityandtheninvalidationoftheads0boiIiliibitorincertainanodicp0tenhalrangePraricV.J.andDradeD.M.,l99O,WangJiaetal.,l99l).InrenzandMansfeld(l98l)rePortedthattheinhibitordesorpti0ncouldproduceonthetheedancediagramaninductivelo0p,whichdePends0nthenabeoftheadd,theadditives,tirneandpotential.Sineeproonessuchasndldiss0lution,adsorph0nanddesorptionofinhibitorandotherreevantionsinteraCtwithcachother,theinhibitordesorpti0nbehaviorrnayprov… 相似文献
53.
二连盆地侏罗系地层热演化史研究 总被引:5,自引:1,他引:4
本文应用磷灰石裂变径迹,镜质体动力学模型等方法恢复二连盆地侏罗系地层的热演化史,二连盆地图参1井磷灰石退火浓度为1600-2774m,对应的退火温度为64-102.7℃,图参1井现今温度小于最高古地温,这是由于二连盆地地温梯度逐渐降低及地层发生抬升和剥蚀所致。根据磷灰石裂变径迹分析和镜质体动力学模型模拟图参1井的热演化史,在晚侏罗世时其经受的最高地温梯度分别为7℃/hm和6℃/hm。侏罗系地层在晚 相似文献
54.
Desorption tests, conducted before development drilling, can predict early production rates of coalbed methane wells. In this study, results from 136 desorption tests from 30 coreholes are compared to subsequent production histories of surrounding wells. Coals studied are from the Carboniferous Pottsville Formation in the Black Warrior Basin of Alabama, USA. The investigation indicates that the best predictor for gas production is ‘‘gas yield at 120 days, divided by sample depth'. This quotient has a higher correlation with actual gas production than other variables examined, including original reserves in-place. Gas content of coal generally increases with depth. However, coal permeability, and hence the recovery factor, tends to decrease with depth. Therefore, coalbed methane exploration should focus on finding the optimal balance between gas yield and depth. Commercially successful wells are characterized by coals with high gas yields at shallow depths. Desorption tests, especially of slowly-desorbing coals, should be run for a minimum of 120 days, or else should be extrapolated to that time if tests are terminated earlier. 相似文献
55.
Geochemical studies of shale gas and conventional reservoirs within the Triassic Yanchang Formation of Xiasiwan and Yongning Field, Ordos Basin show that methane is isotopically depleted in 13C as compared to δ13C1 calculated by the Ro based on the relationship between δ13C1 and Ro. Geochemical fractionation during the adsorption/desorption process of shale system may play a significant part in influencing δ13C1 values of shale gas. Two shale core samples from confined coring of the Yanchang Formation were adopted segmented desorption experiments to examine this phenomenon. The results show that the δ13C1 of desorbed gas changes little in the first few phases of the experiments at low desorption levels, but become less negative rapidly when the fraction of desorbed methane exceeds 85%. The desorption process for the last 15% fraction of the methane from the shale samples shows a wide variation in δ13C1 from −49‰ to −33.9‰. Moreover, δ13C1 of all desorbed methane from the shale samples is substantially depleted in 13C than that calculated by Ro, according to Stahl and Carey's δ13C1–Ro equation for natural gas generated from sapropelic organic matter. This shows some gases with isotopically enriched in 13C cannot be desorbed under the temperature and pressure conditions of the desorption experiments. This observation may be the real reason for the δ13C1 of shale gases and conventional reservoirs becomes more negative in Xiasiwan and Yongning Fields, Ordos Basin. The magnitude of the deviation between the δ13C1 of shale gas and that calculated by Ro may be related to the adsorption capacity of shale or the proportion of absorbed gases. In this way, we may be able to evaluate the relative adsorption capacity of shale in geological conditions by δ13C1 of the shale gas, or by δ13C1 of conventional gas which generated by the shale with certainty. The δ13C1 of conventional gas in Dingbian and Yingwang Fields have no deviation because the TOC value of the hydrocarbon source rock is relatively low. 相似文献
56.
Abstract We carried out hydrothermal experiments in the system dolomite‐quartz‐H2O to track the temporal change in reaction rates of simultaneous reactions during the development of reaction zones. Two types of configurations for the starting materials were prepared: dolomite single crystals + quartz powder + water and quartz single crystals + dolomite powder + water, both sealed separately in gold capsules. Runs at 0.1GPa and 600°C with cold seal pressure vessels gave the following results. (i) In short duration (45–71 h) runs metastable layer sequences involving wollastonite and talc occur in the reaction zone, whereas they disappear in longer duration (168–336 h) runs. (ii) The layer sequence of the reaction zones in short duration runs differs from place to place on the dolomite crystal even in the same run. (iii) The diversity of layer sequences in the short duration runs merges into a unique layer sequence in the longer duration runs. (iv) The reaction zone develops locally on the dolomite crystal, but no reaction zone was observed on the quartz crystal in any of the runs. The lines of evidence (i)–(iii) show that the system evolves from an initial transient‐ to a steady‐state and that the kinetic effect is important in the development of reaction zones. A steady diffusion model for the unique layer sequence Qtz/Di/Fo + Cal/Dol + Cal/Dol shows that the Dol + Cal layer cannot be formed by diffusion‐controlled process and that the stability of the layer sequence Qtz/Di/Fo + Cal/Dol depends not only on L‐ratios (a = /LCaOCaO and b = /LMgOMgO) but also on the relative rate P = (−2ξ1 − ξ2)/(–ξ1 − 2ξ2) of competing reactions: Dol + 2Qtz = Di + 2CO2 (ξ1) and 2Dol + Qtz = Fo + 2Cal + 2CO2 (ξ2). For smaller P the stability field will shift to higher values of a and b. The steady diffusion model also shows that the apparent‐non‐reactivity on the quartz surface can be attributed to void formation in a large volume fraction in the diopside layer. 相似文献
57.
孔隙压力对煤岩基质解吸变形影响的试验研究 总被引:1,自引:0,他引:1
煤层气开采过程中,伴随着煤层气不断地吸附、解吸和渗流,煤体产生变形,极易导致煤和瓦斯突出事故。以晋城天地王坡煤矿为例,通过实验室内试验,模拟煤层气在复杂地层漫长的形成和逐渐开采过程,得到了孔隙压力与解吸量、应变的变化关系,并拟合得出其相应关系表达式,揭示了一些新的规律:(1)初期解吸速度较快,解吸量随时间的增长而不断增加,后期解吸速度减缓,解吸量逐渐趋于稳定;(2)孔隙压力与解吸量、应变呈现抛物线曲线关系,随孔隙压力的升高,吸附和膨胀变形占主导,其值均在增大;(3)存在最小孔隙压力值,随孔隙压力的增大,解吸时间增长,孔隙压力越小,吸附解吸规律越不明显,对于晋城天地王坡煤矿3#煤样,该值在1.0MPa左右;(4)不同加载方式对解吸量和变形量影响较大,先部分加载吸附后全部载荷解吸结果同比加全部载荷吸附解吸结果高13%~77%。试验结果可为煤层气(CBM)抽放安全和煤与瓦斯突出防治提供理论依据。 相似文献
58.
用XRD,SEM和TEM研究新型配合物Cu(C3N2H4)2(C4H5O4)2的超分子结构和微观形貌,并对新型晶体的平衡外形进行模拟计算,结果表明:该配合物分子具有丁二酸桥联的双核铜结构,中心铜离子处在2个咪唑和4个丁二酸以单齿配位组成的八面体中心,在ab平面,分子中有十四元大环,环内Cu(1)-Cu(2)原子间距为0.8031nm,C(2)-C(2′)为0.4183nm;在ac平面,沿着[010]方向分子内呈现凹的六边形纳米级孔洞;沿[100]方向分子依靠弱的氢键作用,层状堆积成三维超分子结构。此外,随着丁二酸的碳链沿[001]方向无限延伸,形成以铜离子为交叉中心的带状拓扑构型。SEM观察到晶体表面形成有明显的凹坑,区域呈现层状阶梯,说明晶体在(100)面遵照台阶-扭折模型呈层状生长结晶。TEM微区形貌像显示晶体存在条纹和缺陷结构,整体保持柱状构型,这与模拟的晶体平衡外形呈柱状一致。模拟结果表明晶体最易外显晶面为(100)面,外显比例达41.247%,这与晶体超分子层沿[100]方向通过氢键作用堆积,键作用力较弱密切相关。 相似文献
59.
在激光BrF5法分析硅酸盐和氧化物矿物的真空提取流程中,通常采用氧气作为工作气体来测定样品的氧同位素组成。这需要使用分子筛吸附并转移氧气到质谱进样系统,而分子筛的活化对于有效吸附和解吸氧气至关重要,否则会引起分析过程中的氧同位素分馏。通过采用13X分子筛进行多组实验分析,笔者发现用不同活化程度或中毒失活分子筛沸石转移时可能存在氧同位素分馏。在低温下分子筛是不能够活化的(或活化不完全),吸附能力很低,所测定的δ18O值是波动的。在200℃马弗炉中预加热24h,然后迅速转移到温度为100℃、真空度为10-3Pa系统中加热12h的分子筛,对氧气吸附能力很强,氧同位素分析的绝对误差为±0.05‰(1σ),能够满足地球化学氧同位素分析的要求。如果分子筛受BrF5污染,其吸附能力大为降低,测定的δ18O值呈下降趋势,氧同位素分馏高达0.7‰。如果分子筛受水汽污染,质谱接受电压不断地降低,存在解吸温度下的再吸附过程,测定δ18O值呈上升趋势。因此,分子筛在使用前要在适当条件下的活化,在发现污染或测量值发生波动变化时要及时更换,否则难以保证氧同位素分析数据的可靠性。 相似文献
60.
There has been a revival in hydrocarbon source rock characterization and development associated with growing interest in unconventional resources, where these fine-grained organic-rich rocks act as both source and reservoir. To-date, the exploration focus on shale reservoirs has been largely on marine systems. Lacustrine source rocks for conventional resources are geographically important, dominating regions such as China, Indonesia, and Brazil's resource-base. However, they have been generally untested for unconventional resources.There are a number of key differences in the nature of these hydrocarbon systems that should be considered when assessing whether lacustrine systems may represent future unconventional opportunities in areas where the conventional resource-base is dominated by lacustrine-sourced oil. Among the key differences between these depositional systems is the greater sensitivity to high frequency climatic variability within lacustrine systems. Lacustrine systems are highly sensitive to changes in the balance between precipitation and evaporation, which may lead to rapid changes in lake level, potentially exceeding 600 m. These changes in depositional conditions are geologically rapid and may occur over periods of thousands of years. Such changes can reduce the areal extent of potentially thick source rock intervals to only those portions of a basin where a permanent deep lake was present. Thus the core unconventional target area may be geographically limited compared with their marine counterpart. Although potentially areally limited, a review of many lacustrine source rocks suggests that their thicknesses are often significantly greater than marine source rocks. An examination of the more distal portions of lacustrine systems, where better source rock potential is present reveals that there is generally limited connectivity between source and conventional reservoir. In these settings, such as the Wind River basin (Waltman Shale), the hydrocarbons remain trapped within the shales, potentially leading to over-pressured hydrocarbon charged systems. Such conditions suggest that although areally limited, viable unconventional targets may exist, if suitable reservoir conditions are present. Finally, the character of the oils produced is different in these settings, with lacustrine oils being waxy and displaying different hydrocarbon generation and cracking kinetics. High wax oils display distinct flow characteristics, being more viscous, and may offer different production challenges than their non-waxy marine equivalents. Additionally, differences in their cracking kinetics may indicate that the timing of gas generation for shale gas plays may differ significantly from marine systems. 相似文献