Geochemical Variability of Saline Brines in South Texas

德克萨斯州南部盐水的地球化学变化

• 批准号: 8706804
• 负责人: Lynton Land
• 金额: $ 10.39万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-01 至 1991-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8706804&HistoricalAwards=false
• 关键词: Geochemical; Variability; Saline; Brines; South

Saline brines in South Texas are now known to exhibit wide ranges in salinity, ionic and isotopic composition. Some formation waters are hypothesized to form in shale-rich sections as water is released by the transformation of smectite to illite, and acetic acid is generated from kerogen. Very saline brines are clearly derived from underlying formations. In one growth fault zone it its hypothesized that elevated geothermal gradients are due to a vertical flux of brine from deeper in the basin. Some brines bear evidence of interaction with basement rocks which underly the Mesozoic-Cenozoic sequence. This project seeks to test these various hypotheses by carefully and systematically characterizing the major element, and isotopic composition of brines from producing oil and gas fields in a 14-county wide area. Spatial variability and relation to structure are critical variables interpreting the ultimate origin of the formation waters, and their role in effecting diagenesis. Brine sampling has proceeded beyond the "reconnaissance" stage in this area (Morton and Land, 1987), and now should be restricted to manageably small areas known to exhibit significant problems which can be addressed by future "saturation" sampling. This project will have significant bearing in our understanding of ore genesis, burial diagenesis, fluid behavior, petroleum generation and sedimentary geochemistry in a region close to DOSECC deep-drilling operations.

现在已知德克萨斯州南部的盐水具有广泛的盐度、离子和同位素组成。 据推测，一些地层水是在富含页岩的部分形成的，因为绿土转化为伊利石会释放水，并且干酪根会产生乙酸。 高盐度的盐水显然来自底层地层。 在一个生长断层带中，假设地温梯度升高是由于盆地深处的盐水垂直通量所致。 一些卤水具有与中生代-新生代序列之下的基底岩石相互作用的证据。 该项目旨在通过仔细、系统地表征 14 个县范围内石油和天然气田生产的卤水的主要元素和同位素组成来检验这些不同的假设。 空间变异性和与结构的关系是解释地层水的最终起源及其在影响成岩作用中的作用的关键变量。 盐水取样已经超出了该地区的“勘察”阶段（Morton 和 Land，1987），现在应限制在已知存在重大问题的可管理的小区域，这些问题可以通过未来的“饱和”取样来解决。 该项目将对我们了解 DOSECC 深钻作业附近地区的矿石成因、埋藏成岩作用、流体行为、石油生成和沉积地球化学产生重大影响。