Analisa Air Fromasi Terbentuknya Scale Kalsium Sulfat Menggunakan Metode Skillman Pada Sumur “R-Eleven” dan Cara Penanggulangannya

Abstract

Scale is a precipitate formed from formation water, Scale is rich in dissolved ions, both in the form of cations and anions. Scale usually forms when mineral deposits occur which can form scale or solid deposits. Scale itself can reduce the ability of rock formations to pass fluids, narrowing the inner diameter of the pipe and tubing resulting in a low flow rate in the well. The scales that are usually formed in oil fields are the CaCO3 and CaSO4 scale types. Scale itself can reduce production due to a decrease in flow rate. To find out whether there is scale formed in the formation water, a test is carried out on the formation water in the laboratory. To predict the tendency of the formation of CaSO4 scale in this field by calculating using the skillman,McDonald and stiff methods. In this well, indications of the possibility of the formation of a CaSO4 scale were found which had previously been found. The formation of a CaCO3 scale in this well occurred in flowlines, perforations or on surface equipment, causing a decrease in production from previously 600 BLPD to 264 BLPD, therefore this is to see if there is The type of calcium sulfate scale formed was calculated using the Skillman, McDonald and Stiff methods at temperatures of 25°C, 30°C and 40°C. After doing the calculations, it was found that the "R_ELEVEN" well formed CaSO4 scale at a temperature of 40°C, because the results obtained from the calculations were that the solubility value of gypsum (S) was greater when compared to the actual solubility value of CaSO4 (S'), which means water is saturated with CaSO4 then the scale in question is formed and precipitated.