Well Annulus Cleaning While Using Stabilizer with an Experimental Flow Loop and its CFD Model

One of the main targets of hole cleaning is increasing drilling efficiency. Insufficient hole cleaning causes several problems. In this paper, the effects of stabilizer application on hole cleaning have been investigated. Some experimental tests were performed by a closed flow loop to analyze the effect of the presence of a drilling stabilizer at different positions in the Bottom Hole Assembly (BHA) and different hole inclinations. To achieve this goal, a stabilizer with four straight blades was designed and conducted in various experiments and simulations. Some experiments were performed by installing the stabilizer in two different positions of BHA “Near Bit” (NB) and “Far From Bit” (FFB) in different hole inclinations. Finally, a prediction model in FLUENT software is proposed to study the behavior of cuttings along the annulus in the presence of a stabilizer for the conditions that cannot be investigated by the experimental setup. According to the comparison between the experimental and simulation data, the presence of a drilling stabilizer has a significant effect on improving the cutting transport and subsequently hole cleaning rate. The results show that stabilizer application assists the hole cleaning at all inclinations except 0° (vertical well). At vertical annuluses, the rotational movement of the stabilizer decreases the cuttings lift force. Moreover, the FFB condition increases the rate of hole cleaning considerably more than NB. Thus, stabilizers by raising the fluid flow turbulency increase the capability of removing the cuttings from the system in most annulus inclinations.