Selecting Drilling Fluid Properties and Flow Rates For Effective Hole Cleaning in High-Angle and Horizontal Wells

Abstract

fax 01-972-952-9435. AbstractThis paper presents a method to determine optimum drilling fluid properties and flow rates to minimize cuttings bed height and circulation time in high angle and horizontal wells. The method uses empirical models relating the cuttings bed height and the bed erosion time to drilling fluid properties and flow rates.Bed erosion tests have been conducted using a cuttings transport facility available at the University of Tulsa. Cuttings bed height as a function of time has been investigated by using variable flow rates (200 -400 gpm) and four different drilling fluid compositions. Experimental results were used together with a non-linear regression analysis program to establish a functional relationship among drilling fluid properties, flow rate, cuttings bed height and the time required to circulate the borehole clean.A numerical example is provided to explain the field application of the method. The sequential calculations involved in determining optimum combination of the Power Law viscosity parameters n and K, and the flow rate to minimize the cuttings bed height and circulation time are also given.Field implementation of the proposed empirical correlations and the new method can aid optimization of circulation practices before tripping, and so reduce the associated risk of nonproductive time.

Fundamentals and Physical Principles for Drilled Cuttings Transport—Cuttings Bed Sedimentation and Erosion

“…This may prevent bed formation and improve hole cleaning efficiency [20]. Thus hole cleaning efficiency relies on non-controllable annular eccentricities to remove cuttings or prevent bed formation [3].…”

“…While drilling a vertical well, the hole cleaning process is easier and does not represent complex challenges due to the small area for cuttings accumulation and the fact that the drilling fluid flows in opposite direction to gravity. Hence, cuttings transportation can be controlled by high viscosity and ensuring good gel formation [3].…”

Contributory Influence of Drill Cuttings on Equivalent Circulation Density Model in Deviated Wellbores

“…Han et al, (2010) carried out an experimental study using CFD on cuttings transport in vertical as well as greatly deviated slim annular hole and the study result showed that pressure drop in a solid-liquid mixture flow increases with mixture flow rate, annular inclination and DP rotation speed [11]. According to Adari, et al, (2000) controlling cuttings transport practically is much dependent on the field conditions encountered. To ensure effective and efficient hole cleaning, transport of cuttings in the annulus usually are not affected by one parameter but a whole lot of parameters [15].…”

“…According to Adari, et al, (2000) controlling cuttings transport practically is much dependent on the field conditions encountered. To ensure effective and efficient hole cleaning, transport of cuttings in the annulus usually are not affected by one parameter but a whole lot of parameters [15]. Despite several studies in the literature on ECD, no significant attention was paid on the influence of drill cuttings on ECD.…”

Simulation and Experimental Study on Cuttings‐Carrying for Reverse Circulation Horizontal Directional Drilling with Dual Drill Pipes

“…In severe cases, the drilling tools may be broken, causing serious engineering accidents, such as sticking [8][9][10]. Many controllable and uncontrollable factors are involved in the hole-cleaning process (i.e., the cuttings-carrying process), such as the flow velocity in the borehole annulus, the displacement of the mud pump, the viscosity of the drilling fluid, the rotational speed of the drill pipe, and the diameter of the bit waterway [11,12].…”