原油中咔唑类参数运移示踪效应的驱替模拟实验

Displacement simulation experiments of migration effect on carbazole parameters of crude oil

油气运移研究对油气勘探与开发至关重要,受原油黏度、复杂化学组成及潜在的多种地质因素影响,原油运移方向与路径的确定难度较大。分子地球化学参数是研究油气运移规律的有效方法之一,实际成藏过程中的这些参数受其形成、相对组成以及演化程度等因素的影响。在实验室条件下可实现单一因素控制下的分子参数效应,采用室内驱替模拟实验的方法,在填砂管上进行油驱水实验,利用C18固相萃取柱分离与富集不同运移距离吸附油中的咔唑类化合物,考察原油中咔唑类化合物的运移示踪规律。结果表明,咔唑类参数1-/4-MCA、1,8-/1,7-DMCA、1,8-/2,4-DMCA、1,8-/2,5-DMCA、1,8-/2,7-DMCA比值均随着运移距离的增加而显著增大,特别是全屏蔽型与全裸露型异构体比值1,8-/2,4-DMCA和1,8-/2,5-DMCA的增长幅度可达63.97%和35.50%,这些参数具备作为良好的运移示踪参数的潜质;而参数苯并[a]/[c]咔唑所表现出的运移示踪规律与前人部分实际油藏运移研究不符,可能是苯并咔唑类化合物的运移受其本身构型和其他地质条件的影响,建议该参数在应用到油气运移示踪研究时须谨慎使用。实验结果可为原油运移示踪参数研究提供有效的方法借鉴,但在实际地质应用时仍需结合分子动力学等手段对相关参数进行验证与优选。

The investigation of oil and gas migration plays a vital role in the field of oil and gas exploration and development.Determining the direction and path of crude oil migration is challenging due to factors such as crude oil viscosity,complex chemical composition,and geological influences.Molecular geochemical parameters are a valuable tool for studying petroleum migration,although they can be affected by factors like compound formation,distribution,and maturation.One approach involves simulating these parameters under controlled laboratory conditions to isolate their individual effects.This study establishes a sandy-packed system to simulate oil-driven experiments and uses a C18 solid-phase extraction column to analyze carbazole compound fractions at different migration distances.The findings indicate that certain carbazole parameters,such as 1-/4-MCA,1,8-/1,7-DMCA,1,8-/2,4-DMCA,1,8-/2,5-DMCA,and 1,8-/2,7-DMCA,increase significantly with transport distances.Notably,fully shielded and fully exposed isomers like 1,8-/2,4-DMCA and 1,8-/2,5-DMCA show enrichment levels of up to 63.97%and 35.50%,making them potential indicators of oil migration.However,parameters related to benzo[a]/[c]carbazole show inconsistencies with previous findings,likely due to intrinsic configurations and varying geological conditions that must be taken into account.The experimental results presented in this study offer insights for assessing specific reservoirs,with a recommendation to also consider molecular kinetics when selecting molecular parameters.