They stated that for both muds with same rheological properties, water base mud has a better performance in the wells with 40°–50° inclination. ( 1993) investigated lime cutting transport in water base mud and invert emulsion oil base mud.

The results of their work showed that flow regime and rheological properties of the drilling fluid are the key parameters in well cleaning operation and water with turbulence flow has a good performance in well cleaning. They used a pipe line with 9 ft length, inclination angle from 0° to 90° and 3.5 in. ( 1990) studied drilling cutting transport in deviated wells.

Also, they called the angle between 40° and 50° as critical angle since cutting bed thickness is formed and cuttings are slipped on the cutting bed in the critical angle. They stated that for a constant mud flow rate cutting bed thickness increased by increasing inclination angle. ( 1986) published the results of experimental studies with various drilling fluids in plastic pipe lines with inclination angle from 0° to 90°. 1993 Okrajni and Azar 1986 Sifferman and Becker 1992 Hussaini and Azar 1983) and by modeling approach (Nguyen and Rahman 1998 Wazed 2002 Akhshik et al. Some of affective parameters on wellbore cleaning have been studied by some researchers experimentally (Tomren et al. Also, there is an optimum point for drilling cutting density at 8.5 in which stress applied on the drilling string will be minimum.Įfficient wellbore cleaning is an important goal in a drilling operation especially in horizontal and deviated wells since it can prevent problems such as stuck pipe, lost circulation, high torque and drag, loss of control on density ECDs, and finally it can reduce the cost of the drilling operations (Ozbayoglu et al. By increasing two times of drilling cutting density/operational density, cutting precipitation ratio increased 200%. The results showed that by increasing two times of drilling fluid density/operational density, cutting precipitation ratio decreased 32.9% and stress applied on the drilling string and pressure drop increased 4.59 and 5.97%, respectively. A systematic validation study is presented by comparing the simulation results against published experimental database. The effect of drilling fluid and cutting density on the pressure drop, deposit ratio and string stress on the cutting transport has been investigated. To this end, this article focused on the affecting parameters on the cutting transport by computational fluid dynamic (CFD) modeling and real operational data. Cutting transport is an important goal in drilling operation especially in horizontal and deviated wells since it can cause problems such as stuck pipe, circulation loss and high torque and drag.

Bulking and cutting ratio