Abstract
With approximately 70% of the world's petroleum located in poorly consolidated reservoirs, sand production is a global challenge. This paper explains a new well testing concept to optimise and maximise the production potential. This is achieved by finding the limit of topside sand production when the sand comes from the reservoir or is accumulated in the wellbore. If the sand comes from accumulation in the wellbore, it is removed by a cleanout operation (bottom-up) and measured by weight until the well stabilises on lower sand production to be confirmed coming from the reservoir. The next step will be to adjust the well flow to the acceptable sand rate (ASR) while still flowing at a rate not to accumulate sand in wellbore. This is difficult to achieve without proper sand measurement tools. A patent-pending well- testing method has been developed using Dual vessel desander solids management systems with regular well testing information. This method provides a complete picture of the sand production at the same time as the production potential of the well is discovered and realised. This is done while simultaneously reducing the effects of erosion from solids and without sand being transported to downstream process facilities.
A dual vessel desander unit is installed during well testing to ensure sand protection for the downstream process facility. The system combines several data elements to measure solids production in real-time. The real-time data enables operators to tune wells individually for increased oil and gas production (Typically above the ASR production flow level). At the same time, ensuring produced solids are removed, measured and handled upstream of the process facility.
The method shows several benefits; including improved guidelines for a well start-up (also often referred to as a well bean-up) to avoid sand to the surface, identifying unrealised production potential while maintaining solids below the ASR, and lowering overall sand production that enters the production separator by regularly cleaning wells with dual vessel desander systems.
A case study from the North Sea is shared. An Operator utilised the method to reduce their coiled tubing cleanout operations due to continuous surveillance of sand producing wells that were brought into clean-up mode via the desander before they lost too much pressure and ceased production. ESG improvement over eight years, as the operator eliminated 20 coiled tubing clean-out operations, reducing operations cost, risks of heavy lifts, personnel mobilisations, and emissions per barrel produced.
