Experimental evaluation of improvement of water base drilling fluid's rheological properties on formation damage

Formation damage due to the penetration of drilling fluid particles, as chemical damage, can reduce the natural permeability and production. Formation damage removal methods in wells are very costly and often unsuccessful. The aim of this study was to investigate and improve the rheological properties of water-based drilling fluid with different amounts of additive, the effect of these drilling fluids on the formation damage, and modification of some properties to reduce this damage. Five types of water-based drilling fluids were considered and the effect of xanthan gum concentration and a rheological reducing agent on the formation damage was investigated. The formation damage results in barite drilling fluid showed that although the addition of a rheological reducing agent could improve these properties to some extent, but caused more formation damage. However, barite fluid with the lowest concentration of xanthan gum had less formation damage than other concentrations. Fluid A with better rheological properties showed more formation damage. Although solid particle-free additives are preferred in the industry, the results showed that by improving the rheological properties of the drilling fluid, this damage can be controlled.

Keywords:

Formation Damage , Drilling Fluid , Rheological Properties , Return Permeability , Xanthan Gum Polymer.