Abstract

The oil industry is continuously evolving and the need to be more dynamic and efficient is always present. A new downhole Coiled Tubing (CT) technology is now available, capable of performing intervention with both conventional CT tools, and wireline cased hole tools in the same well, allowing optimization of time and reducing any restriction on logging time, by providing a continuous power supply. Additionally, it is possible to execute diagnostic distributed acoustic and temperature sensing if more details are required for a specific zone.

Older techniques used in coiled tubing logging sometimes require several runs to achieve the objective. In the well reviewed in this paper, two runs were performed with conventional techniques without achieving the purpose of the intervention. The high gas production rate of the well and the inability to have real-time monitoring of the Production Logging Tool (PLT) data were significant obstacles to success using these methods. This paper presents an optimized intervention wherein a milling operation, a production log, and pressure buildup test are necessary to understand the production profile of the well, identify the gas-oil ratio per reservoir, understand if additional production is impeded because of cross flow or casing leaks, and identify reservoir pressure of the zone.

The real-time hybrid integrated system was designed with an open architecture to accommodate any wireline or mechanical tool available in the industry to address operator challenges, such as milling operations where the operator was able to monitor the weight on the bit, the torque, and the differential pressure through the bit; or a PLT job operation where the operator was able to monitor the weight on the bit, and use Casing Collar Locator (CCL) and/or Gamma Ray (GR) sensors to correlate with wireline logs, all in a single CT rigup without the need to change the hybrid bottomhole assembly (BHA), CT string, nor the CT Connector (CTC).

Real-time communication with the wireline tool is achieved with a conductor line installed in the CT, which also provides power to the tools. Communication with the integrated bottomhole sensors and distributed profiling capability utilizes the fiber optic lines to transmit the data in real time. Because the communication of the tools is independent, there is no concern over running combinations of multiple downhole sensors.

This case study is the first known instance wherein CT was used in conjunction with downhole tools that were supplied with continuous power to sensors to enable measurement of parameters while milling followed by a PLT job where the same cable not only powered but communicated with the wireline tools.

Because of the flexibility illustrated during the operation of the study, a campaign of production and injection logging jobs could be executed in the field without any communication issues or nonproductive time, increasing the efficiency of the intervention.

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