Recently, horizontal wells in Saudi Arabia have been targeted to improve the recovery efficiency and enhance the reservoir drainage of tight reservoirs. Evaluating the performance of high flow rate horizontal wells with high gas-oil ratio and producing below the bubble point is difficult and often non-unique with conventional production logging measurements. The challenges arise from the following reasons:

  • Gravitational segregation of the oil, water and gas in the well bore,

  • Complicated fluid velocity profiles due to phase separation,

  • Mixed fluid flow regimes,

  • Long and undulating well bores.

For the first time in Saudi Aramco, a high flow rate horizontal well with excessive gas oil ratio has been logged with a coiled tubing conveyed integrated production logging tool. The horizontal well penetrated a heterogeneous carbonate formation with a long transition zone. The objectives of running the integrated production logging tool were the following:

  • Determine the flow profile and estimate the entire contributing length,

  • Locate the gas entry points and determine the gas flow rate, if possible,

  • Evaluate the performance of this integrated production logging tool run for the first time in a Saudi Aramco well producing below the bubble point.

This paper presents a case study of such an application in the difficult environment. The results showed that the entire horizontal section was contributing to the total liquid flow. Gas inflow was difficult to quantify with the exception of the toe of the well, where the gas hold-up was higher than 70% and the gas flow rate was successfully computed. The results are discussed in detail and recommendations are made to improve the interpretation of gas inflow in this environment.

You can access this article if you purchase or spend a download.