Effective Slimhole Cementing in a Challenging Environment - A Gulf of Thailand Case History

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe successful development of a light weight slurry system for cementing long intervals at high temperatures in three dimensional multiple stacked gas zone wells, has been achieved in the Gulf of Thailand. The cementing system has been developed to successfully complete progressively more difficult wells, starting with conventional large bore wells and tubing plus packer completions, and later down-sizing into single monobore wells whereby the tubing is cemented in place. The problems associated with the down-sizing of the wells are further increased by more challenging well paths and higher temperature fields. Many problems and risks were overcome to complete this task successfully. These changes have posed new challenges in primary cementing.Like the well size, the slurry system has also undergone a refinement and improvement process. The local industry has gone from dry blended slurry systems to all-liquid additive slurry systems saving considerable dollars, whilst realizing large gains in slurry flexibility, ease of mixing and improved logistics. Whilst developing and realizing these gains, the system has been refined and successfully applied to smaller, hotter and more difficult wells.This paper presents the concerns associated with cementing these challenging wells where remedial cementing has been effectively eliminated. The processes related to this success, evaluation methods and field results will be discussed.

Performance of Selected Natural Bio-Polymers for Fluid Loss Control in Water-Based Drilling Fluid: A Literature Review

“…Drilling fluid is formulated to specifically possess required properties to perform intended functions (Todd, 2001;Abduo et al 2015;Shu et al 2016). They can be described as thixotropic shear-thinning fluids with a yield stress (Adesina et al, 2012).…”

“…Shu et al (2016) posited that most problems in the drilling operation are associated to erroneous drilling fluid formulation. Drilling fluid is essential for cooling and lubricating the drilling bit, transporting cuttings out of the hole, preventing formation damage, stabilizing the pressure in the well and aiding formation stability (Todd, 2001;Jerry et al, 2005;Shu et al, 2016). The cost of loss of drilling fluid to the formation can be significant.…”