Analysis Of Formation Damage During The Drilling Of Horizontal Wells

Numerous studies have been carried out on Formation damage in vertical wells but less investigation was conducted in horizontal wells this therefore necessitates development of an approximate filtration theory through a compressible cake medium. A mathematical model was developed to describe the mechanisms and processes of filtration into the Formation through a compressible filter cake during drilling of horizontal wells. Goodmans integration technique was adopted for the solution taking into consideration the effects of non-linearity and gravity. The result shows that the Cake thickness buildup at different values of constant of non-linearity is very small also depth of invasion was observed to increase at the beginning of drilling and reduced as time went by. The rapid decline in Solid pressure indicates more damage in horizontal wells than other models used for vertical wells. An approximate analytical solution combining both the steady and transient components has been successfully applied to solve the filtration theory equation developed for horizontal wells. The model is easily applicable to estimate important values needed to know the status of the formation during the drilling of horizontal wells.