Apply Cost Effective Multiple Cementing Technologies to Sidetrack in Air Drilling Environment in Chiya Khere Field

Abstract

Chiya Khere field development plan is to drill a lateral hole from existing pilot holes. While in the drilling phase, severe losses were hindering the drilling plans due to lack of effective solutions to sidetrack in air drilling environment. Historically, losses circulation pills were never effective to cure the losses in highly fractured zones, the drilled wells in this field were abandoned using mechanical barriers (Bridge plugs) to facilitate the lateral plan, which was increasing the field development time and cost. Also, due to difficulties to obtain open-hole mechanical bridge plugs the well project duration was extended significantly, furthermore, isolating the loss zone using mechanical tools is the least preferred primarily due to availability and then setting failures in the big hole. In this paper, a newer approach will be presented to demonstrate the specialized technique to cure total losses which resulted in a significant reduction in the operational cost to drill these laterals in Chiya Khere field without changing the casing designs or postponing the project due to no viable solution and explains detailed techniques to overcome the challenges. Some techniques to combat severe losses are pumping loss circulation pills, drilling under balance, and pumping cement plugs. A new and unique loss control strategy was introduced in one of the recently drilled well in this field, in which two pills of solid free spacer separated by a fiber carrier fluid were pumped for instant bridging and viscosifying at the downhole were injected into the losses zone to create a temporary lock-up prior to pumping a rapid gelled cement plug for permanent isolation, once the losses been controlled a firm base cement plug was placed to spot a high compressive strength cement plug (kickoff cement plug), Applied proposed techniques led to having successful results in which rapid gelled cement headed by losses circulation material (LCM) solution combination cured the losses and successfully isolated the bottom of the hole which facilitated to placement a basement plug then kick off cement plug, and tag at the designed top of cement (TOC) to drill the lateral to the new planned trajectory.