Prior to undertaking any drilling campaign, the process of offset well analysis is of paramount importance. When performed accurately and presented properly it provides the basis for all design work and risk analysis. A new feature in the modelling software Petrel called Drilling Risk Manager offers the ability to be able to carry out the offset well analysis in a 3D environment. The aims of this study is to investigate the means in which the Drilling Risk Manager feature of Petrel can aid in de-risking wells during the offset well analysis process and to highlight the potential efficiency savings that can arise. The efficiency savings of using Petrel have been highlighted through the use of a case study focusing on the initial development work that was carried out in conjunction with TAQA for their North Cormorant and Cormorant East fields in the UK continental shelf. In this study a Schlumberger engineer worked closely with TAQA on classifying the offset well data for the field, populating the data into a 3D shared earth model in Petrel and then using this model to perform a full risk analysis. For TAQA, using Petrel has made it easier to clearly view all of the drilling hazards that have occurred on the North Cormorant and Cormorant East fields. Using all of the extra information, two wells drilled on the Cormorant East field were well prepared for hazards which are common in the area. Using the 3D model to aid in the risks analysis process saved a considerable amount of time in comparison to the usual method employed by TAQA. Schlumberger are in the process of fully developing the use of Petrel as a means of derisking wells in mature fields in to a value added service that can be provided throughout a drilling campaign. Projects are being developed for several UK Operators in this field, incorporating well bore stability and drilling analysis in order to provide efficiency savings throughout a drilling campaign.