Study of Relationship Between Interlayer Thickness and Shearing Strength at Cement-Formation Interface
GU Jun
CHEN Xue-feng
Abstract：Hydraulic fracturing is a main process for an efficient development of low permeability oilfield.The interlayer channeling located at the cement-formation interface in the interlayer is the main cause of the fracturing failure or the sudden water flooding.So,it is very important to study the relationship between the interlayer thickness and the shearing strength at cementformation interface.Based on the proposed simulation experimental method,the numerical simulation results show that the shearing strength decreased with the decreasing of the interlayer thickness which is less than 1 m.The concept of channeling coefficient of interlayer interface ξ and related mathematical model were pioposed.When ξis close to 0,the channeling resistance ability of interlayer interface become higher.Only when ξis more than 1,the channeling at cement-formation interface will occurs.The interlayer thickness has no significant effect on the shearing strength when the interlayer thickness is less than 1 m.Whether the channeling of the thin interlayer occur is determined by the fracturing pressure,thickness of mud cake,hole size and shearing force at cement-formation interface,and has no correlation with the interlayer thickness.
Keywords：fracturing with thin barriersinterlayer channelingshearing strength at cementformation interfaceinterlayer thicknesschanneling coefficient of interlayer interface
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 219-222,258 )