Schlumberger

Technical Paper: Prediction of Injection Induced Formation Shear

Society: SPE
Paper Number: 151840
Presentation Date: 2012
 Download: Prediction of Injection Induced Formation Shear  (1.41 MB PDF) Login | Register

 

Abstract

Formation integrity is a critical confinement factor in any injection process such as waste injection, CO2 capture and storage, and thermal/pressure injection in oilfields. Rock can fail in tensile, shear or in combination of complex modes. In situ stresses variation caused by injection may shear the caprock posing continued risk of containment breach. We developed an integrated approach to predict the alteration of in situ stresses and shear failure potential by combining data from sonic logs, image logs, mini-frac test data, formation pressure measurement, and rock mechanical core test data. In this approach, three-dimensional Mechanical Earth Models containing the reservoir, overburden, under-burden and side-burden were constructed. Coupled simulations were then run between dynamic reservoir model and geomechanical model to quantify stresses change induced by injection. The resulted formation shear and surface heave will then be calculated regarding the location and timing of occurrence during the planed injection operations.

The methodology has been applied to several steam injection case studies in Northern Alberta oil sands area, Canada. Our analysis indicated that three years of steam injection would cause up to 2 MPa stresses contrast; formation shear failure was forecasted to occur earlier than formation tensile failure at a same time step; the calculated surface heave due to steam injection was around three 3 cm. The simulation results enabled the optimization of injection scheme and proactive monitoring plans to avoid catastrophic events.

Related services and products

 
Request More Information

Petrotechnical Expertise in Geomechanics

Real-Time Drilling Geomechanics
From predicting drilling risk in your first well to maximizing production and recovery from mature assets, our multidisciplinary collaboration can help you throughout your geomechanics operations. Visit Interpretation Services for Geomechanics page