DESCRIPTION:
This paper provides a comprehensive and critical review of external filter cake formation during dynamic (cross-flow) filtration with main focus on petroleum engineering applications. Numerous researches have been done during last decades to investigate the cake buildup mechanisms, structure and effects of various parameters on cake properties, flux decline and stabilisation. However, a consistent hypothesis to explain the main cake buildup mechanisms and structure has not been devised yet due to numerous laboratory and field observations that can be attributed to different physics mechanisms.
The paper discusses mechanisms of cake buildup from several laboratory and field studies and presents recent findings of dynamic filtration tests. This includes discussion of the effect of chemical conditions (salinity, pH and ion valence), particle size, particle size distribution, shear rate, cake compressibility, particle flocculation, particle concentration, applied pressure and particle deformation from numerous experimental and field reports.
APPLICATIONS:
A comprehensive collection of dynamic filtration test results can be used in design of drilling fluids for minimizing fluid loss and prediction of well injectivity impairment due to external filter cake formation during PWRI or sea water injection.
RESULTS AND CONCLUSIONS:
Experimental observations are classified and tabulated in a comparative format. Limitations and contradictions of experimental findings are discussed in detail and possible future road map is presented. Analysis of previous works supports the strong effect of chemical and hydrodynamic factors on mechanisms, structure and properties of external filter cake. Several experimental evidences confirm the optimum conditions of water salinity to minimize permeate flux.
SIGNIFICANCE:
External filter cake properties highly affect the fluid loss during drilling operations. It also plays an important role in well injectivity decline during low quality water injection. With increasing interest in application of Nanoparticles in drilling and EOR operations and hot topic of low salinity water-flooding, understanding previous studies provides a road map for future research and design. The paper summarises the results of previous researches critically and addresses the applications in drilling and completion fluids, produced water reinjection (PWRI) and sea water injection.
