Worldwide First Successful Production Logging of Tri-Lateral High Temperature Coiled Tubing Drilled Sour Gas Well, Performed in a Single Run Using Innovative Reentrance System Without Whipstock Guides

Abstract

The job results from an operation using a wireline-operated lateral access tool (LAT) with a production logging tool (PLT) on E-coil are presented. The objective was to successfully identify, enter and acquire production data in each of the openhole laterals as well as the main borehole in order to quantify production and identify any cross-flow. This operation is enabled by the use of a wireline-operated LAT. The tool can identify where the lateral window is located in the well and provide orientation data. With the LAT, the bottom sub can be indexed to enable entry into the lateral, while sensors package would provide positive confirmation and identification of a particular, targeted lateral. The system is compatible with a number of mono-cable logging tools and can be deployed using both E-line as well as Coiled Tubing. This paper describes the operation in detail and discusses the output and evaluates the results, which demonstrate the efficiency and accuracy of finding and entering the laterals. The operation was conducted on a well in Saudi Arabia which was drilled using underbalanced coiled tubing drilling (UBCTD) technique in 2013 and included three, slim openhole laterals. In early 2014, the well was put on production with unknown contribution from each of the lateral sections, but interlateral cross-flow was suspected, leading to the need for intervention. A number of approaches were considered with special consideration given to a new technology that had been developed locally and run with success on some other oil and water wells in the region. This technology had not been utilized previously in slim openhole wells with predominantly gas production. Challenges were anticipated regarding how some of the sensors would perform over two critical areas: identification of the lateral windows and confirmation that the lateral had in fact been entered successfully. The results of this operation demonstrate that the sensors can operate successfully in this environment. The operator was able to acquire critical reservoir information about each of the openhole laterals as well as the main bore, enabling further understanding of well production and reservoir depletion efficiency. This case study demonstrates the innovative application of LAT to enable the production logging (PLT) and evaluation of slim openhole laterals in a gas well drilled with UBCTD compared to previous cases which were predominantly oil producers and water injectors.

Corrosion resistance of steel for coiled tubing units

“…According to the results of studies of total corrosion in five working solutions, it was found that the corrosion rate in acidic [22,23] solutions (I, II) is significantly higher than in neutral [24] (III, IV, and V). For ease of analysis, the results of corrosion studies are presented separately for acidic and neutral working solutions.…”

“…The samples were completely immersed in a corrosive medium and kept in a thermostat at a temperature of 70°C to reproduce real operating conditions [21,22].…”