Pioneering a New Method to Prevent Scale in Deep Water, High Pressure Reservoirs - A Gulf of Mexico Case Study

摘要

Production of hydrocarbons in deep water reservoirs involves the economical flow of hydrocarbons from the reservoir to the point of sale. One important consideration is effectively preventing / handling solid deposits which can be both organic (i.e. paraffin, asphaltenes) and inorganic (i.e. calcite, barite, halite) in nature. These deposits can cause catastrophic blockage in pipelines, subsea equipment and impair fracture conductivity and well performance. To prevent deposition and lost production inhibitor chemicals are typically delivered downhole via tubulars, injected at points along flow lines and risers and as an additive to fracturing fluids. Installing and maintaining such injection systems in these very challenging environments can be expensive to the operator of such facilities. A new delivery system has been developed which utilizes an infused and encapsulated ultra-high strength porous proppant (UHSPP). The stresses of these deep, high pressure reservoirs requires proppant that can resist closures up to 20,000 psi and previous attempts of using solid inhibitors in these environments have typically sacrificed conductivity. The use of this UHSPP does not negatively impact conductivity and allows for delivery of inhibitors in previously unreachable areas. The delivery system allows inhibitor chemicals to be released at a slow, controlled rate when the proppant comes in contact with produced fluids and results in a highly efficient, reservoir based chemical delivery system. Typical treatments are designed to last for years of production. This paper will present a case study of the use of this new technology in owery tertiary wells in the Gulf of Mexico. These wells have been treated with an inorganic scale inhibitor using a multi-functional UHSPP. This paper will also describe how substrate type and pore structure can be engineered to maintain conductivity at very high closure stresses. It will also show how semi-permeable membranes can be tailored to specifically control the release of these inhibitors upon contact with production fluids. This paper will prove useful for all completion, production and facility engineers engaged in offshore operations, and can also be adapted similarly to onshore wells. The cost savings from utilizing a UHSPP delivered chemical system can provide a significant reduction in operating expenses.