Substantial cost and schedule overrun in several high-profile, remote deepwater offshore projects have occurred globally, over the past couple of years. With this has increased exponentially the need for understanding how best to attain deepwater project portfolio management success. Deepwater project portfolios are complex and high risk with a lot of uncertainty. They present unique challenges and require capital intensity to initiate projects. This book focuses on investigation of the critical success factors required for successful deepwater development. With the use of the Statistical Package for Social Sciences (SPSS) tool, thirteen critical success factors were established along with project delivery schedule, project budget and portfolio management strategy as impacting on project success. It also identified that some critical success factors in mega construction projects can apply to deepwater oil and gas projects. Project management is indispensable for business results. The work is useful for deepwater oil and gas project management practitioners in the petroleum industry who will encounter issues of cost and schedule overrun, strategy and resource allocation.