光纤原位地应力测量方法研究OA

Accurate in-situ stress determination is vital for evaluating the mechanical state of subsurface rock and supports key petroleum engineering operations such as wellbore stability,hydraulic fracturing design,and fracture propagation control.Increasingly complex geological settings expose the limitations of conventional measurement methods in resolution,accuracy,and continuity.Fiber-optic sensing provides a means for continuous and high-precision monitoring under such conditions.This work presents an in-situ stress measurement method that combines fiber-optic strain sensing with a reverse differential strain mechanism.By applying internal pressure to drive microfractures around the borehole from closure to reopening,the method infers in-situ stress from the mechanical response of t he rock.Laboratory physical simulation experiments were conducted to establish the theoretical framework and measurement workflow.Results show that fiber-optic strain data effectively capture rock anisotropy and heterogeneity,enabling estimation of in-situ stress ratios through the reverse differential strain model.Compared with the Kaiser acoustic emission method,the approach yields an 8%～24%error range,averaging 16%.Although still in its early phase,the method offers a promising technical pathway for in-situ stress determination in oil and gas engineering and provides a foundation for future refinement and application.