烃源岩的有机酸生成及其影响因素的模拟实验研究

Experimental Study on the Generation of Organic Acids from Source Rocks and Its Effect Factors

不同温度下地层水-烃源岩相互作用模拟实验结果表明：（1）在整个实验温度范围内（60—300℃），均有有机酸的生成，有机酸的总浓度在35．4mg／l至153．9mg／l之间，其中在100℃和140℃的温度下浓度最大，其它温度下浓度相对较低；（2）在低温（60℃）条件下，成熟度相对较高、有机碳含量较大的烃源岩，有利于生成有机酸，但是在中温（140℃）和高温（180℃、220℃和300℃）条件下，有机酸的生成受有机碳含量、成熟度和碳酸盐含量的多重影响；（3）中低温（60℃和140℃）时，随着碳酸盐含量的增加，有机酸浓度表现为逐渐降低的趋势，表明在60-140℃，有机酸对碳酸盐的溶解和沉淀起主要的控制作用，而高温（180℃、220℃和300℃）条件下，碳酸盐的溶解和沉淀作用受有机酸和CO2的共同控制，从而导致有机酸浓度与碳酸盐的关系变化复杂。

The experimental results of formation water-source rock interaction in different temperature suggest the following results：（ 1 ） organic acid is generated in the experimental temperatures （60 ～ 300℃ ）, the total contents of organic acids is between 35.4 mg/l and 153.9 mg/l. The contents of organic acids are higher in the temperatures of 100℃ and 140℃ than that other temperatures; （2） the source rocks with high maturity （Ro ）and high total organic carbon content（TOC） are favorable to the generation of organic acids in the low temperature（ 60℃ ）, but the generation of organic acids are commonly controlled by the maturity （Ro）, total organic carbon content（TOC） and carbonate content of source rocks in the middle（ 140℃ ） and high temperature（ 180℃ ,220℃ and 300℃ ） ; （ 3 ） the contents of organic acids gradually decrease with the increase of carbonate content in source rocks in the low and middle temperature （60℃ and 140℃ ）, it suggests that the dissolution and precipitation of carbonate are mainly controlled by organic acids in the range of 60℃ to 140℃, but the dissolution and precipitation of carbonate are commonly controlled by organic acids and CO2 in the high temperature（ 180℃ ,220℃ and 300℃ ）, it makes the correlation between organic acids and carbonate complicated.