In the process of evaluating the acquisition of overseas oil and gas assets, evaluators make efforts to collect relevant information, but the completeness of the information is often restricted. Simultaneously, making prompt decisions is crucial for acquiring overseas oil and gas assets, while the evaluation period typically ranges from 2 to 3 months. Therefore, within a limited timeframe, it is necessary to design engineering plans and estimate investments based on the collected data. Estimating drilling investments, in particular, requires a comprehensive understanding of factors such as reservoir conditions, development methods, natural environment, and fluid properties specific to the project. Under the constraints of limited time and data availability, there is a high demand for efficiency in engineering evaluations. The accuracy of investment estimates is directly related to the reasonableness of project investment pricing decisions, making it crucial to accurately estimate drilling investments. To address this, this paper employs fuzzy mathematical methods to estimate the investment for an individual well in a project in the Middle East. The results demonstrate a mere 8.16% difference from the actual investment, which falls below the 10% threshold and adheres to the accuracy requirements of investment estimation. This indicates that the proposed method is capable of accurately estimating drilling investments within the constraints of limited time and data resources, providing effective decision support for the acquisition of overseas oil and gas assets. The method holds practical value and contributes to enhancing the scientific rigor and accuracy of evaluations.