UK requirements in the Borehole Sites and Operations Regulations 1995 do not specify the minimum size of drilling platforms. They require the operator to ensure that the drilling platform is designed, constructed, erected and maintained and has sufficient stability to afford adequate protection

for employees and to withstand the environmental forces anticipated at the site. In doing this, HSE would expect an operator to make an assessment of the type of drilling platform required. This would involve taking into account: the environmental factors (e.g. geology); the type of well (e.g. the depth and the diameter of the metal tubing used to construct the well); the weight to be suspended from the platform's lifting hook; the particulars of the site; and the risks associated with the type of work to be performed (e.g. drilling or extraction). In practice, this means the drilling platform will need to be as big as needed to conduct the specified operations safely."