The complex nature of the reservoir dictated comprehensive formation evaluation logging that was typically done on wireline. The high angle designed for maximum reservoir exposure, high temperature, high pressure (HTHP), differential reservoir pressure and wellbore stability challenges necessitated a new approach to overall formation evaluation. The paper outlines Formation Evaluation strategy that reduced risk, increased efficiency and saved money, while ensuring high quality data collection, integration and interpretation. After review of all risks, a decision to utilize Managed Pressure Drilling (MPD) for wellbore stability, Logging While Drilling (LWD) to replace wireline and Advanced Mudlogging Services was implemented. The Formation Evaluation team utilized LWD resistivity, neutron, density and nuclear magnetic resonance logs supplemented with x-ray diffraction (XRD), x-ray fluorescence (XRF) and advanced mud gas analysis to ensure comprehensive analysis. The paper outlines workflows and procedures necessary to ensure all data from LWD, XRF, XRD and mud gas are integrated properly for the analysis. Effects of Managed Pressure Drilling on mud gas interpretation as well as cuttings and mud gas depth matching are addressed. Depth matching of all data, mud gasses, cuttings and logs are critical for detailed and accurate analysis and techniques are discussed that ensure consistent results. Complex mineralogy due to digenesis and effect of LWD logs are evident and only reconciled by detailed XRF and XRD data. The effects of some conductive mineralogy are so dramatic as to infer tool function compromise. The ability to determine acceptable tool response from tool failures eliminates unnecessary trips and leads to efficient operations. The final result of the above data collection, QC and processing resulted in a comprehensive formation evaluation interpretation of high confidence. Finally, conclusions and recommendations are summarized to provide guidelines in Formation Evaluation in similar challenging highly deviated, HTHP, complex reservoir environments on land and offshore.

Cement quality is an important well integrity consideration to ensure proper hydraulic sealing. Traditionally, wireline cement bond logs have been used extensively in the Jurassic formation of North Kuwait. The case study well presented in this paper had an 80° inclination and 3,000 ft of a 6-in. open hole, which has remained opened for quite some time. Cement evaluation was required inside the 7 5/8-in liner to determine the cement quality behind the liner and integrity of liner shoe. This information is important for achieving a successful of multistage completion for the producing interval in the 6-in open hole. The target interval had a vertical depth greater than 14,000ft from mean-sea level with a well deviation more than 80°. Four operational days were required to run drill pipe conveyance of conventional cement evaluation wireline tools. This operation would have exposed the 2,500ft of open hole to potentially collapsing situation due to the time dependence of the wellbore stability. The capability of logging-while-drilling (LWD) multipole sonic tool for evaluating the cement quality was considered, as there was plan to acquire open hole log data using LWD technology, which included the LWD multipole sonic tool. While running in the hole to the open hole section, the LWD multipole sonic tool can acquire sonic-based cement evaluation data inside of the 7 5/8-in liner. This operating method consumes no rig time while obtaining the well integrity information. This paper presents the case study, along with the LWD multipole sonic tool theory for measuring cement bond quality index, operation preparation, and the results of the data acquisition.