摘要
储层的渗透率应力敏感性在油气勘探开发领域有着重要的研究价值。实验样品选自4类典型的碳酸盐岩储层,制取Φ2.5cm×5cm的基块、天然裂缝和人工裂缝圆柱体样品,开展渗透率应力敏感性及岩石力学实验研究,并分析岩石物性及岩石力学性质对碳酸盐岩储层渗透率应力敏感性的影响。实验表明,碳酸盐岩渗透率应力敏感性可以选用应力敏感性系数法评价,方便于不同区块、不同层位、不同岩性储层应力敏感性的对比;碳酸盐岩基块、天然裂缝和人工裂缝岩样的应力敏感性系数均值为0.22、0.49和0.63,应力敏感程度逐渐增强;碳酸盐岩的应力敏感性系数与渗透率的相关性较差,但整体呈减小的趋势;劈裂法制取的人工裂缝岩样的应力敏感性随机性较大,较难真实地反映天然裂缝岩样的应力敏感性;应力敏感程度与岩石力学性质相关,岩石弹性模量越大应力敏感性越弱;建议加强应力敏感性微观机理及数值模拟研究。
Permeability stress sensitivity of formation is of great research value in oil ＆ gas exploration and development. Experiment samples with Ф2.5cm× 5cm,which were classified as matrix,natural fracture and artificial fracture,were selected from four types of typical carbonate rocks. The researches on permeability stress sensitivity and rock mechanics were carried out, and the effect of permeability stress sensitivity influ- enced by physical and mechanical characters of rock was analyzed. Results show that permeability stress sensitivity can be evaluated by stress sensitivity coefficient for the purpose of conducting a contrastive study in different oil blocks, formations and lithology. The stress sensitivity coefficients of carbonatite matrix samples,natural fracture samples and artificial fracture samples were 0.22,0.49 and 0.63, respectively. It shows a trend of steady increase. The correlation between the stress sensitivity of carbonatite and the per- meability is poor. It＇s hard to precisely reflect the stress sensitivity of natural fracture because the randomness of stress sensitivity of the artificial fracture sample is bigger. Stress sensitivity is closely related to the mechanical properties of rock. The higher value of rock elastic modulus, the weaker the stress sensitivity. It is expected to strengthen the researches on micromechanism and simulation of stress sensitivity.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2014年第3期409-413,共5页
Natural Gas Geoscience
基金
国家重点基础研究发展计划"973"项目(编号:2010CB226705)
国家科技重大专项(编号:2011ZX05005-006-02)联合资助
关键词
碳酸盐岩
应力敏感
渗透率
流固耦合
裂缝
Carbonate rocks
Stress sensitivity
Permeability
Fluid-structure interaction
Fracture
