Improvement of Hole Cleaning Through Fiber Sweeps

Abstract

Hole cleaning is often more difficult during drilling of inclined wells. The resulting poor removal of cuttings can lead to problems such as borehole pack-off and excessive ECD, which are both difficult and expensive to resolve. Fluid sweeps are commonly implemented when normal circulation cannot adequately remove cuttings from the borehole. Field reports have indicated that specialized fibrous-type materials enhance cleaning performance when added to fluid sweeps. Yet, understanding of the behavior of this improvement remains inexact. This paper presents a comparative experimental investigation of the hole cleaning performances of fiber sweeps, conducted with different drill pipe rotation speeds and fiber concentrations. Experiments were carried out in an inclined flow loop apparatus with an inner rotating drill pipe. The hole cleaning performance of fiber-containing sweep fluids using different fiber concentrations (0%, 0.05%, 0.1%, and 0.2%, by weight) and varying drill pipe rotation speeds (0 to 90 rpm) was evaluated. Sweep efficiencies were compared in terms of the measurement of cuttings bed heights before and after circulating the sweep fluid.The results indicate that significant improvement associated with higher fiber content requires a commensurate increase in drill pipe rotation speed. With lower or no pipe rotation speed, increasing fiber concentration yields less dramatic returns. Pairing high fiber content with rapid pipe rotation resulted in enhanced performance over the control sweep, which contained no fiber, but relatively low concentrations did not surpass the control.With the increasing need in the industry to drill extended reach or otherwise inclined wells, there is greater potential to develop problems stemming from inadequate hole cleaning. This research gives insight into the specific interaction of sweep fiber and pipe rotation with the cuttings bed, and with each other. Deeper understanding of fiber sweeps would inform infield decisions when dealing with poor hole cleaning.

Review of Hole Cleaning in Complex Structural Wells

“…Some field applications were also conducted, and made some achievements [28,29]. However, the flow behavior, hydraulics, and cuttings-transport efficiency of fiber sweeps is less known, and some experiments [8][9][10] about fiber sweep were conducted.…”

“…Cheung et al [10] also carried out experiments with different drillpipe rotation speeds (0 to 90 rpm) and fiber concentrations (0%, 0.05%, 0.1%, and 0.2%, by weight) in TUDRP 's small indoor flow loop. The results indicate an increase in fiber concentration improves the hole cleaning efficiency with high pipe rotation or flow rate.…”

“…The Table indicates fluid flow rate, mud rheology, inclination, pipe rotation, ROP, particle size, pipe eccentricity, mud density have a certain effect on cuttings transport, and multi-factor interactions also were observed. In addition, the effect of fiber sweep on hole cleaning was studied by many experiments [8][9][10].…”

Experimental Study of Hole Cleaning Performance of Underbalanced Drilling at Downhole Conditions

“…The effectiveness of using fiber sweep for hole cleaning and reduction of cutting bed thickness in horizontal and highly deviated sections was recently considered [1,2,10]. Valluri et al [10] investigated the effect of rheology of the sweep fluid on sweep efficiency under LPAT and EPET conditions.…”

Horizontal Drilling Well Proposal in West Qurna Oil Field (Iraqi Oil Field)

“…The mechanism of an active hydro clean drill pipe (EHCDP) for transport cuttings and hole cleaning was introduced by [9]. The authors in [10] carried out experiments with different drill pipe rotation speeds (0 to 90 rpm) and fiber concentrations (0%, 0.05%, 0.1%, and 0.2%, by weight) in TUDRP 's small indoor flow loop. Their results indicate an increase in fiber concentration improves the hole cleaning efficiency with high pipe rotation or flow rate.…”