At different penetration depths, mud-component invasion creates multizone structures in the vicinity of the wellbore. These structures include external mudcake (mud particles and mud clay deposited at the sandface), internal mudcake (which is formed by mud particles invaded into the reservoir formation), and mud-filtrate invaded zone.
We present a new technique for estimating empirical parameters of both external and internal mudcake by combining laboratory data on mud flooding experiments and measurements of the profile of the invaded mud components by X-ray microcomputed tomography (XmCT), image processing of core cross-section photography, and ultrasonic wave scanning.
The technique is validated on flooding experiments with simple ("model") muds: slurry of bentonite clay, suspended solid particles and polymer Xanthan.
Examples of reconstructed profiles of invaded mud components (solid particles and bentonite clay) as well as the procedure of determining internal mudcake parameters are provided.