This paper details the preparation and temporary deployment of a Multiphase Flow Meter (MPFM) for a series of multi-rate well tests carried out on high gas-liquid ratio (GLR) production wells. The MPFM incorporated specific design features to permit accurate measurement of liquid rates in high Gas Void Fraction (GVF) production streams and was prepared as a skid mounted unit for ease of deployment, hook-up and demobilisation. MPFMing was chosen in order to eliminate the need to flare or recompress depressurised fluids. This permitted the wells to be flowed at flowrates similar to their normal production rates, which maximised the benefit of the data obtained, without the need to deploy expensive and space consuming additional equipment. The ease and speed of deployment and hook-up demonstrates that such equipment can provide well performance data similar to that collected by a conventional temporary well test spread. Cumulative well performance curves generated from the data collected showed good correlation with production station data supporting previous conclusions regarding the accuracy of MPFM's. The maintenance of this accuracy in the difficult high GVF flow regime vindicates the use of the particular equipment model and design chosen. The small footprint, reduced crew size, and elimination of flaring makes this system an attractive option for testing on unmanned facilities, in environmentally sensitive areas and when space constraints appear prohibitive.

The traditional need to carry out all well operations from a rig can be expensive and delays valuable well construction programmes. Rigless intervention, including the use of subsea wireline lubricators and installing subsea Xmas trees on wire, utilising a Dynamically Positioned (DP) intervention vessel has long been accepted in some areas of the world as a costeffective and efficient alternative to traditional rig-based methods.In 2005 it was recognised internally that the ability to intervene without a traditional rig would be of potential future benefit. An aspirational work programme was developed including both well operations such as subsea Xmas tree (SSXT) change out, well abandonment and production enhancement operations was developed. The scope generated was sufficient to justify the mobilisation of a suitable vessel and the necessary specialist equipment such that these operations could be completed. It was also recognised that the vessel would offer further options for construction support, commissioning start up support and field maintenance activities. The actual 1 st job undertaken of SSXT installation on Vincent project was not recognised as a possibility until late 2006.To date 7 SSXT installation operations have been completed successfully in approx. 370m of water on the Vincent field in Australia, this was followed by wireline intervention to commission wells for operation to/from the host facility. A number of plugged and abandoned wellheads were also severed and recovered from the seabed. The vessel was also utilised extensively for other subsea operations. Operations are ongoing to complete the expansion of the Vincent project and a number of production enhancement opportunities are being planned for the near future including PLT surveys, water shut offs, and Gaslift valve installation. This paper will detail the operations undertaken and the issues to be managed to ensure safe and cost-effective execution. Furthermore the paper examines the unique challenges of translating experience gained to date to the Asia-Pacific region, to deeper water depths, and will discuss the lessons learnt from the planning and operations phases of the project. These will include details of the modifications required to the vessel to convert her from her previous role as a large Supply Vessel (PSV), including the critical elements of the conversion required in order to ensure appropriate Class registration and the successful award of an Australian Safety Case covering all safety critical operations.Lastly the paper will examine the potential benefits Rigless intervention can offer and the additional cost benefits of incorporating other non-well related activities into the vessel programme.