This research involves a comprehensive geotechnical investigation at the jack-up rig location on the Natuna offshore platform, Southeast Asia. The primary objective of this investigation is to provide detailed geotechnical data to support engineering and design work for the Natuna Block development project. The collected data is used to ensure that the soil conditions at the site meet the technical requirements for rig operations, offering more accurate guidance in determining foundation parameters. At the planned location for the jack-up rig installation, the geotechnical investigation included two composite boreholes and piezocone penetration tests (PCPT) with a maximum depth of 36 m at two points: WHP-P4S and WHP-P4P. Additionally, a sampling borehole with a maximum depth of 36 m was conducted at WHP-P3B-BH, along with an extra PCPT borehole of the same depth at WHP-P3B-CPT. Each borehole and penetration test were designed to identify the geotechnical characteristics of the site, serving as a basis for planning and executing the rig operations. This evaluation provides a detailed assessment of the leg penetration of the jack-up rig “X” at the drilling location in the Natuna Sea. The study covers several key aspects, including: Evaluation of piezocone penetration test (PCPT) results and geotechnical data analysis at each leg location of the rig, an in-depth analysis of the jack-up rig spudcan penetration, a crucial element in assessing the stability and safety of rig operations, recommendations based on the data and analysis results regarding the rig leg penetration, along with further discussion on the implications of these findings for rig operations at this site. Through a systematic and data-driven approach, this study provides the necessary technical guidance to ensure that the rig foundation design meets the expected safety and performance standards, thus supporting smooth operations on the Natuna offshore platform.