CORROSION STUDY ON THE EFFECTS OF FLOWBACK WATER IN SHALE GAS RESERVOIR

Shale gas is found within the shale formation which is a tight formation. Hence, to improve the low permeability of this formation hydraulic fracturing technique is used in extracting the shale gas. The injection of fracturing fluid into the wellbore is to cause the formation rock to crack and allowed the flowing of gas into the well. When production of shale gas starts, some of fracturing fluid known as flowback water will flow back to the surface and this flowback water cause corrosion to happen on the production casing. This study has been conducted to investigate the effects of reservoir conditions and flowback water toward downhole equipment; and to identify a suitable material for downhole equipment during the production of shale gas. The scopes of this study are focusing on the corrosion problems that could occur on the downhole equipment, efficiently select the materials to maintain the integrity of the equipment and the effect of reservoir condition such as presence of reservoir impurities to the corrosion or degradation rate. The methods used for corrosion mitigation is by using corrosion resistant alloy (CRA) as the downhole equipment material for shale gas production. Software called Electronic Corrosion Engineer (ECE) is used to calculate the corrosion rate of tubing in some specific condition of shale gas well and to select the most suitable tubing material for that condition.