Thermochemical sulphate reduction (TSR): experimental determination of reaction kinetics and implications of the observed reaction rates for petroleum reservoirs
Thermochemical sulphate reduction (TSR): experimental determination of reaction kinetics and implications of the observed reaction rates for petroleum reservoirs
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DOI：
10.1016/j.orggeochem.2004.01.005
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发表时间：
2004-01-01
影响因子：
3
通讯作者：
Worden, RH
中科院分区：
文献类型：
--
作者：
Cross, MM;Manning, DAC;Worden, RH
热化学硫酸盐还原 (TSR) 是一些高温石油聚集中产生大量 (10-80%) H2S 的原因，已在金钛反应容器中在 280-350 摄氏度和 250-500 巴以及原位 pH 值在 5.2 至 6.8 之间进行模拟，使用在线流体采样和分析来监测连续反应进度。 TSR 的计算活化能为 142 kJ/mol，在乙酸水溶液和元素硫存在下，硫酸盐水溶液的半衰期在 150 ℃ 下为 1650 年，在 100 ℃ 下为 372,000 年。在数百万年前被填充的许多储层中，硫酸盐矿物和石油持续共存，因此无法通过减少速度来控制。实验还表明，当压力和 pH 值被限制在一系列实际的地下值时，它们都不会显着影响 TSR 速率。实验同时表明，乙酸脱羧的速率强烈依赖于压力，升高的压力会导致反应速率降低。这一定是因为脱羧涉及正体积变化，并提供证据表明所有导致净体积增加的有机分解过程，例如在超压油藏中，干酪根分解会相对延迟。 (C) 2004 Elsevier Ltd. 保留所有权利。
Thermochemical Sulphate Reduction (TSR), responsible for substantial quantities (10-80%) of H2S in some high temperature petroleum accumulations, has been simulated in gold-titanium reaction vessels at 280-350 degreesC and 250-500 bars and in-situ pH values between 5.2 and 6.8 using on-line fluid sampling and analysis to monitor continuous reaction progress. The calculated activation energy of TSR is 142 kJ/mol with a half life of aqueous sulphate in the presence of aqueous acetate and elemental sulphur of 1650 years at 150 degreesC and 372,000 years at 100 degreesC. The continuing co-existence of sulphate minerals and petroleum in many reservoirs, filled millions of years ago, thus cannot be controlled by the rate of reduction. The experiments also show that neither pressure nor pH significantly affect the rate of TSR when they are limited to a range of realistic subsurface values. The experiments coincidentally revealed that the rate of acetate decarboxylation is strongly pressure dependent with elevated pressure leading to a decreased rate of reaction. This must be because decarboxylation involves a positive volume change and provides evidence that all organic breakdown processes that lead to a net volume increase, e.g. kerogen breakdown, will be relatively retarded in overpressured reservoirs. (C) 2004 Elsevier Ltd. All rights reserved.