PREDICTION OF CALCIUM SULFATE FORMATION IN THE WELLS OF THE ARLANSKOYE OIL FIELD

Abstract

One of the reasons that reduce well operation efficiency is the formation of inorganic salts from the produced water deposited in the well bottom zone and on the surface of oilfield equipment. The control of deposited salts is a very laborious and not always effective process, therefore it is necessary to use methods of salts preventing. Prediction of inorganic salts deposition allows to choose the optimal mode of well operation and take measures to prevent salt formation. This article describes the composition and conditions of salt deposition during the Arlanskoye oil field develop- ment. At the same time, methods for preventing of their formation were considered and the calculation of determining the saturation of the pro- duced water with gypsum was made. Gypsum deposits are one of the most common types of deposits in the wells of the Akineevsky area of the Arlanskoye oil field. In order to main- tain reservoir pressure at the Arlansk oye oil field, which is at a late stage of development, waterflooding is used. As a result of mixing of incom- patible waters and supersaturation of the solution, salts precipitate out. This leads to well operation mode disruption and equipment wear. As a result of the calculations, it was found that in one of the wells selected for the study there is a possibility of the gypsum deposition. This implies the need to use technologies to prevent the inorganic salts deposition. If complications at oil production are detected, it is possible to choose the optimal well operation mode and introduce technologies to prevent salts deposition, resulted in lowing rate of well productivity.