The main objective of this study was to develop a competency model and study the relationships of intensive training, quality assessment, motivation, and skill pool expert on the core competencies of workers serving in the oil and gas industry in Yemen to maintain sustainable productivity, development of the country's economy, employees' safety and clean environment in the O&G production. A preliminary study and questionnaire were used to assess the technical trainees' perceptions in operation, maintenance, and safety of five oil companies in Yemen. The sample was 350 trainees in this study. The data were analyzed by using SPSS software and Structural Equation Modelling (SEM). The result found that intensive training, quality assessment motivation has a significant positive effect on employees' core competence, however, the skill pool expert specifically in line supervisor and coach has a strong effect on employees' core competencies. Multiple linear regression analysis was used to test a hypothesis. This study was conducted in five oil companies and among 350 trainees only. For this reason, the results cannot be generalized to other contexts, where the other companies not interested and implemented conventional training programs, characteristics, and peer support from the work environment, were outside the scope of the study. This study will add value to the efforts of the oil exploration and production board in Yemen, by providing an increased understanding of the factors that create competent technicians based on the competency model

The Competency model is vitally essential for the protection of petroleum companies workforce during operations, commissioning, shutdown, troubleshooting, maintenance and any lack of the core competencies of employees would lead to production interruption, damage assets, environments and company reputation, likewise this research focused on several aspects including intensive training, quality assessment to identify the core competency level in term of competency model, wherefore purposive sample was employed and 350 technical employees from operation, maintenance, and safety division ,meanwhile qualitative and quantitative study conducted among expertise and oil and gas employees , and collected data analyzed and interpreted by statistical methods (SPSS and SEM ). The result of data interpretation provides affirmation of significant positive effect of intensive training on employees' core competence with limited specific gaps in safety issues and troubleshooting and recommending action plan to bridge such gaps. The impact of this factor resulted into 60% of core competency success