Abstract

Scale deposition in oil and gas wells has been challenging for many years. Scaling severely decreases flow capacity and hydrocarbon production as a result of reduction in the tubular diameter. Various techniques have been developed and implemented in the field, including mechanical (drilling, milling, and jetting) and chemical solutions, to remove different types of scale. This paper presents a novel laboratory approach to determine an effective mechanical scale-removal material used in jetting tools. This approach thoroughly screens possible scale-removal materials and enabled the identification of a new material that is acid-soluble in nature, water-insoluble, and possesses little/mild strength. These properties ensure the effective removal of various types of scale without damaging the tubulars.

A novel laboratory approach was devised to meet the necessary criteria for an effective scale-removal material, which included sphericity and roundness analysis, single-grain crush test, photomicrographs, abrasion test, water solubility, and acid solubility tests. Following the new approach, several potential products were analyzed to determine the best material for scale removal using a jetting tool. The evaluation was performed, focusing on scale removal requirements and cleanout while ensuring tubular protection.

The approach in this study was designed while considering the actual well scenario and various types of scale. The variety of materials used had different responses in the laboratory evaluation; the material that best fulfilled the criteria was recommended for scale removal using a jetting tool. The material identified using the new approach effectively removes scale deposits without damaging the tubular. In addition to its non-damaging characteristic with respect to the tubular, the new material is also easily removable after the scale removal treatment.

This study proposes a novel laboratory approach and describes the use of this approach to identify new mechanical scale-removal product. The approach was developed for the laboratory evaluation of scale-removal materials blasted through a jetting tool; its use resulted in a cost-effective mechanical scale-removal solution that uses a jetting technique and that is more efficient than the conventional materials currently used.

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