Using a Novel Fiber Cement System to Control Lost Circulation: Case Histories from the Middle East and the Far East

摘要

Eliminating or controlling lost circulation during drilling orcement operations is a costly and time-consuming process.Traditional treatments include lost circulation materials(LCM), cement, crosslinked polymers, dilatent slurries,reinforcing plugs, and silicate systems. The general practice isto cure the losses before proceeding to the cementingoperation. The mixed results of such treatments plus the factthat cementing operations sometimes proceed even withpartial or total losses have led to the development of a newadvanced-fiber cement system (AFCS). This paper willdiscuss the properties and the mechanism of the AFCS and itssuccessful applications as a solution to lost circulation in theMiddle East and the Far East.AFCS forms a fibrous network across highly permeableformations, induced and natural fractures, and vugularformations to prevent and stop the losses during remedial orprimary cementing operations. Unlike conventional fibers thatnormally are difficult to disperse in the cement slurries andtend to plug surface and downhole equipment, AFCS does notsuffer from such drawbacks.Laboratory tests have shown the effectiveness of AFCS inplugging different hole sizes. The efficiency of this systemwas enhanced in the laboratory when combined with highperformancelightweight cement slurry (HPLW), an optimizedparticle size distribution system. Several jobs in Abu Dhabishowed substantial success rates compared with traditionallost-circulation treatments. This was confirmed by cementreturns to surface and cement coverage across the lostcirculationzones.Other field locations utilized AFCS in cement plugs, topjobs, and primary cementing operations through different floatequipment, liner hangers, and even coiled tubing without anyplugging problems.