Abstract
This paper discusses the leakage of hydrocarbons up a fault into an overlying sand that is cut by the fault. The supply of hydrocarbons is continuous until exhaustion of the main source below the sand. At the same time that hydrocarbons can be filling the sand, production is also allowed from the sand components. Hydrocarbons may also bypass either or both components of the cut sand if their respective capacities have been reached, so that there can be a time dependent loss from the lower sand component or the upper sand component or both, as they are filled and drained by production. Numerical illustrations show how the start time of production for each sand influences the bypass and “topping-up” of the sands, as well as the influence of the fractions of the hydrocarbon flow that can be diverted to each of the sand components of the hydrocarbon flow are allowed to vary. In short, an Excel program built upon such ideas has many of the capabilities needed to describe the broad features of leakage, production, topping up, and loss from such sands, as occur specifically in the Eugene Island 335 field as well as in many other fields.