Evaluating hydrocarbon reservoir by wireline logging and open is the best technique over the years. In an independent geological area, open hole logs provide information about the well as well as the data that can be used in offsetting the well in the future. But with all this at hand, there is still some apparent setback for open hole logging this arises from rig time that is needed to be expanded to condition the hole to log and later reset the hole to cement. Another drawback in open hole logging is that it loses some of its usefulness when the well has been cased up. This implies that the established open hole logs cannot be rerun to reevaluate the hydrocarbon reservoir performance once casing sets. To re-evaluate these cased reservoirs, the pulsed-Newton capture, and inelastic GST* Gamma Spectrometry Tool can be used successfully.
This article will discuss the method in which cased reservoir monitoring, and re-evaluation device can lead to creative interpretation techniques that permit the replacement of open hole logs with cased hole evaluations in heavy oil projects.
Estimation of hydrocarbon potential is more standard and accurate when utilized data is obtained from reservoir assessment. This evaluation is critical in the independent geological area. Information gathered from cores; drill stems test earlier before casing and logs run led to key decisions such as where to complete the well, how the well can be completed, and the production mechanism needed for the well.
Running open hole logs have become one of the best forms of reservoir assessment because cores and test are not necessary for it. This type of reservoirs assessment requires hole state that permits open hole logging tools to get down to potential hydrocarbon horizon. Open hole is economical form of evaluation in deeper well as well as in non-developed areas
In a shallow area, the time dedicated for open hole rig time becomes the considerable amount of the total rig costs. By using cased hole logging for critical formation assessment on closely spaced new well in the heavy oil, the reservoir has proven more economical.
Open hole log data lose some of the relevant data once casing has been set. The reservoir is then needed to be monitored by logs run in a casing. Most Oil companies doubt some of the cased hole assessment technique because the raw data have been difficult to be compared with raw extensive logging data. This doubt has buried the need for evaluating reservoir condition and performance.
In conclusion, it will be good to choose cased hole logging system because the pulsed neutron capture and inelastic GST tool have been tested and used by some oil company. And it has been successful with accurate logging data in their cased reservoirs .it is also able to re-evaluate these cased reservoirs with much efficiency some of the countries in which this is utilized is Canada.