Methane hydrate stability in pore water: A simple theoretical approach for geophysical applications

被引:154
作者
Dickens, GR
QuinbyHunt, MS
机构
[1] UNIV MICHIGAN, DEPT GEOL SCI, ANN ARBOR, MI 48109 USA
[2] UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV ENERGY & ENVIRONM, BERKELEY, CA 94720 USA
关键词
D O I
10.1029/96JB02941
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Geophysicists have recently expressed an interest in understanding how pore water composition affects CH4 hydrate stability conditions in the marine environment. It has previously been shown in the chemical engineering literature that CH4 hydrate stability conditions in electrolyte solutions are related to the activity of water (a(w)). Here we present additional experimental data in support of this relationship and then use the relationship to address issues relevant to geophysicists. Pressure and temperature conditions of CH4 hydrate dissociation were determined for 10 solutions containing variable concentrations of Cl-, SO42-, Br-, Na+, K+, Mg2+, NH4+, and Cu2+. The reciprocal temperature offset of CH4 hydrate dissociation between the CH4-pure water system and each of these solutions (and for other electrolyte solutions in literature) is directly related to the logarithm of the activity of water (lna(w)). Stability conditions for CH4 hydrate in any pore water system therefore can be predicted simply and accurately by calculating lna(w). The effect of salinity variation and chemical diagenesis on CH4 hydrate stability conditions in the marine environment can be evaluated by determining how these processes affect lna(w) of pore water.
引用
收藏
页码:773 / 783
页数:11
相关论文
共 52 条
  • [1] [Anonymous], GLOBAL BIOGEOCHEM CY
  • [2] [Anonymous], CHEM ENG RES DES
  • [3] [Anonymous], P ODP SCI RES
  • [4] [Anonymous], 1990, P OCEAN DRILLING PRO
  • [5] BANGS NLB, 1993, GEOLOGY, V21, P905, DOI 10.1130/0091-7613(1993)021<0905:FGATBO>2.3.CO
  • [6] 2
  • [7] BROWN KM, 1995, P OC DRILL PROGR SCI, V141, P259
  • [8] INTERACTION BETWEEN THE CHILE RIDGE AND CHILE TRENCH - GEOPHYSICAL AND GEOTHERMAL EVIDENCE
    CANDE, SC
    LESLIE, RB
    PARRA, JC
    HOBART, M
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 1987, 92 (B1): : 495 - 520
  • [9] A 3RD-SURFACE EFFECT ON HYDRATE FORMATION
    CHA, SB
    OUAR, H
    WILDEMAN, TR
    SLOAN, ED
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1988, 92 (23) : 6492 - 6494
  • [10] CLEGG SL, 1991, ACTIVITY COEFFICIENT, P279