Publications

When drilling new wells, standard open hole logging, especially triple combo, is a basic dataset required to evaluate reservoir characterization. This plays an important role in identifying and incorporating all the characteristics of the formation reservoir and fluid into optimizing hydrocarbon production. Formation evaluation is used, where the lithology, porosity, and formation fluid type become the key data to determine the perforation intervals, which results in the foal of optimal production.

In every cased hole logging job, there are complexities and challenges that require a comprehensive understanding of the well challenges for reservoir monitoring projects. In a recent case study, the main challenge arose when the open hole triple/combo log data couldn't be acquired due to the hole condition. Despite several attempts, open hole logging tools were held up before logging into the reservoir sections. Considering all possible operation risks that might occur in the future, the open hole logging operation was ended, with decision to continue with cased hole saturation log as the only reservoir view prior to perforation.

A pulsed neutron tool is used to logged across the entire well to evaluate reservoir saturation through casing, after the well is drilled and cased. The situation was challenging with no open hole (OH) data in the reservoir section. Only mudlog and open hole data from the old neighbouring well were available to understand the reservoir formation in general. Understanding the impact of heavy mud filtrate invasion into the formation increased the complexities of the reservoir saturation calculation. This paper discusses the key aspect of the method to solve for reservoir saturation using the independent formation property measurements from pulsed neutron tool in a critical well with limited open hole data.