Oil Fields Scale Deposition Prediction Methodology

Abstract

Abstract Oilfield scale costs are high because of drastic oil and gas production decline, frequent pulling of down-hole equipment for replacement, re-perforation of the scaling producing intervals, reaming and re-drilling of the plugged oil wells, stimulation of the plugged oil-bearing formation and other remedial work-over. As scale deposits around the well-bore, the porous formation becomes plugged and may be rendered impermeable to any fluids. In most of oil and gas fields scale deposition in surface and subsurface production equipment has been recognized to be one of the major operational problem. Problem will be more critical in Water flooded fields where wells will suffered from flow restriction because of scale deposition within the oil producing formation matrix and the down-hole equipment, as well as scale deposits in the surface production equipment. Some of the Oil Fields have been water-flooded with formation seawater. Compatibility tests have indicated probable deposition of scale in surface and subsurface production equipment. This paper outlines the physical and theoretical prediction for down-hole scale deposition in the water flooded fields. Water is the main substance, which is responsible for scale build up problem. In order to study the circumstances behind the scale build up problem, following the new methodology which can be applied to predict the different types of scale build up before start to be precipitated. From the samples of the complete water analysis reports, Scale Indexes were calculated to define the different scales that can be precipitated at different production nodes/conditions. This paper showed that different types/amounts of scale accumulation can be precipitated from the selected water samples since the super saturation conditions of water occurred. It also described the control of scale inhibition programs which could be carried out to control down-hole scale deposition and scale inhibition treatment that could be implemented to overcome the scale deposition, before scale problem will be occurred. Scale control can also been controlled/managed properly by continues updating the new scale index calculations methodology described in the probable problematic water flooded reservoir.