Can Sourceless Density LWD Replace Wireline in Exploration Wells? Case Study from Saudi Arabia

Abstract With the search for hydrocarbon reaching extreme and difficult frontiers worldwide, the use of tools that allow real-time monitoring of operations, such as logging while drilling (LWD) has become increasingly more attractive for both drillers and geoscientists, to safely drill and properly evaluate target formations. In this paper we examine an alternative where a sourceless density LWD tool was used. It offers the assurance of not using nuclear sources to minimize hazards at the rig site. The tool uses a pulsed neutron generator instead of a chemical source. This allows for safe operation, safe transport and pollution free environment, in particular, in exploration wildcat environment where little is known about the area and the risks are higher. The objective of this paper is to compare sourceless density LWD tool's performance to wireline using common logs to test the validity of this new technology replacing wireline in exploration wells. In this investigation, real-time applications of LWD data are presented. First, general factors contributing to differences between LWD and wireline log responses are analyzed. Then, similar curves between LWD and wireline are compared. And, the formation evaluation results based on wireline versus LWD measurements are discussed. The findings of this study will help reduce the uncertainty associated with the validity of sourceless LWD in replacing wireline in exploration wells. This has many implications for operational efficiency, duration and cost.