Novel 2 1/8-in. Real-Time Downhole Data Monitoring System for Coiled Tubing Operations
Authors: Livescu S. , Blanco D. A. , Vacik L. , Kubicki K. 
Published: September 2015

A recently developed 2 ⅛-in. intelligent coiled tubing (ICT) system combines real-time downhole data monitoring with the capability to simultaneously provide downhole power, significantly improving operational efficiency and accelerating well recovery in all types of CT operations. From milling, stimulation, and well cleanouts to gas lifting, camera services, logging and perforating operations, this novel system can provide accurate, real-time downhole monitoring of high-resolution depth correlation, differential pressure, and temperature data.

The novel real-time downhole communication system consists of a non-intrusive electrical conductor wire, surface hardware and software, and a versatile 2 ⅛-in. bottomhole assembly (BHA) that incorporates the conductor release assembly, casing collar locator (CCL), pressure, and temperature sensor package, and BHA release function. Switching between different applications is as simple as changing out the BHA, which reduces the need to rig-up and rig-down and leads to operational time and cost savings. The main advantage of this system is that it eliminates the downhole uncertainties. For instance, using the real-time downhole depth, pressure, and temperature data, the CT field crew can react to changing conditions, make decisions based on dynamic downhole events, and eliminate missed or wasted runs.

Several case studies are presented in this paper. First, an ICT conveyed camera operation was effectively performed in an onshore lateral well in North America to locate the damaged casing. Previously, several unsuccessful attempts with a wireline, camera, and tractor system resulted in 50 hours of total lost time to the operator. Second, a complex cement milling, cleanout, and perforating operation was performed to kick off an onshore well in Netherlands. The real-time CT communication system was used to perforate the well and to have control over its bottomhole pressure, especially during the kick off stage. Third, an ICT system was used in a mature offshore well in Brazil with increasing water cut to run inflatable plugs to isolate the water zone. Fourth, a complex drifting, logging, jetting, zonal isolation, and scale removal operation was performed in a mature offshore well in Brazil to decrease its water cut. Fifth, a matrix acidizing operation was performed in a deepwater cased well in Brazil. The logging profiles showed that the well had low well productivity. Using the ICT system, the perforations were accurately located due to the CCL data and the acid treatment was enhanced due to the downhole pressure and temperature data. Placing the acid at the right spot significantly increased the well productivity.

The paper describes the novel real-time data monitoring system and discusses the data acquired during these field operations. The system performance and benefits confirmed during the five operations are presented. These findings outline the versatility of the 2 ⅛-in. ICT system, the predictability of successful operations resulting from using this system, and the cost and time savings for operators.