The influence of reservoir parameters on damage to carbonate formations by drilling fluids
Damage to formation, reservoir, drilling fluids
Damage to the formation is a challenge encountered during operations carried out by the petroleum industry. This problem consists of reducing the permeability of the reservoir due to mechanical, chemical, biological or thermal factors caused by rock-fluid interaction. The damage directly impacts production and injection into the well, generating operational and financial losses for the company. In well drilling, damage caused by drilling fluids is common. Drilling fluid's main functions are to promote stability to the well walls, control hydrostatic pressure and the formation of filter cake (glue), which helps reduce damage to the formation. When the composition of the drilling fluid does not meet the characteristics of the reservoir, the formation of the grout is compromised and its performance leads to problems such as invasion of filtrate, migration of fines, blockage of pores and consequently, the appearance of damage. Understanding reservoir properties, such as permeability, rock length and fluid present in the reservoir, is essential to make adjustments to the process to prevent or mitigate damage, especially in carbonate reservoirs that have a heterogeneous composition, a particular characteristic that significantly contributes to the extent of damage caused by drilling fluids. The present work aims to investigate the influence of reservoir parameters on damage to carbonate formations by drilling fluids. The present work aims to investigate the influence of reservoir parameters on damage to carbonate formations by drilling fluids. To this end, permeability return tests will be carried out using a commercial water-based fluid previously characterized in terms of its physicochemical properties. In these tests, the effect of the initial permeability of the rocks (low, medium and high), their length (3 and 6 inches) and the fluid present in the reservoir (brine and olefin) will be studied. In this way, we seek to understand how these parameters influence the return of permeability, based on the analysis of the invasion radius and the magnitude of the damage.