This research paper explores the organizational behavior changes that occur during a merger and acquisition (M&A) process within the Oil and Gas (O&G) industry, specifically focusing on Schlumberger's acquisition of Cameron International Corporation in 2015. The study aims to identify key factors leading to organizational change, understand the impact of acquisitions on employees and management, analyze the effects of behavioral changes on profit margins and revenue, and evaluate strategies for mitigating adverse impacts. The research employs an exploratory research design with a cross-sectional approach, utilizing primary data collected through surveys from employees of both Schlumberger and Cameron. The findings contribute to understanding the challenges and opportunities associated with M&A activities in the O&G sector, emphasizing the importance of effective communication and change management to ensure successful integration and maintain employee morale and productivity. The research also discusses the potential positive and negative impacts of M&A activities on the revenue and reputation of the organization, highlighting the significance of cultural fit and addressing employee concerns to prevent attrition and maintain a competitive advantage.