The influences that clay minerals have on tight sandstone elastic behaviors and the interpretation of associated mechanisms remain poorly understood. One of the important reasons for this lack of understanding is that natural tight sandstones have complex mineral compositions and contain diverse clay types. To fill this gap, we have innovatively synthesized nine tight sandstones that contain different clay types and content. The experimental results show that saturated smectite-rich tight sandstones caused a significant weakening of the shear modulus while a reducation in the shear modulus after saturation for kaolinite-rich samples was not noticeable. We preliminarily suggest that smectite hydration is the main mechanism that causes this phenomenon. Using the differential Kuster-Toksöz model with a dual-porosity scheme, we can simulate shear weakening. Therefore, if the natural tight sandstone contains clay minerals, we must consider the clay mineral type and content, as well as their effects on the elastic properties of the rock.
Presentation Date: Tuesday, September 17, 2019
Session Start Time: 8:30 AM
Presentation Start Time: 8:30 AM
Location: 305
Presentation Type: Oral
