Optimization of Sandstone Stimulation Techniques in Kuwait Reservoirs: Comparative Field Analysis and Formulation of Nitrified Mud Acid Fluid System

Abstract Sandstone acid stimulation remains a technical challenge due to formation sensitivity and heterogeneous mineralogy. This paper evaluates stimulation jobs executed in Burgan oil field under Burgan Sandstone formation, highlighting the performance differences associated with chemical formulations and operational sequences. The objective focuses on defining data-driven optimal practices operationally and chemically intended to enhance formation productivity index while reducing water cut by controlling clay migrations and diversions of mud acid. A comprehensive and comparative analysis of sandstone stimulation jobs for wells B1 and B2 based on treatment recipes, additives, operational sequences, and post stimulation production. Key variables examined included acid type, concentration, chemical additives, and pre/post-treatment operational practices. The job design approach focuses on full wellbore displacement strategy prior to acidizing the pay zone, utilizing nitrified mud acid system diversion assistance combined with a balanced clay control formulation. Following Acidizing technique, well activation by Nitrogen was conducted. This integrated practice was subsequently evaluated, indicating its effectiveness in contributing to formation cleaning and mitigating acid-induced damage. The analysis showed jobs in both cases executed on B1 and B2 outperformed other traditional sandstone stimulation techniques due to its use of Nitrogen (N2) for deeper penetration and diversion, and well-balanced dosage treatment. Jobs performed using higher acid volumes or no clay additives reflected deficient stimulation or formation damage. Organic acids presented low reactivity in sandstone. The presence of both clay stabilizers and control agents proved essential in preventing clay swelling and fine migrations. Including wettability modifiers in pre- and postflushes aided interfacial tension reducers cleanup of fine removals and water cut reduction. Based on these findings, it was observed that the utilization of low concentrations mud acid will improve production by allowing less precipitations with minerals into the formation creating a proper dissolved damage and open pathway for production. This newly adopted formulation is expected to offer improved cleanup, minimized post-stimulation damage, and safer water cut control. The methodology sets a new direction for sandstone stimulation in acid-sensitive formations which showed success in production that jumped from 30% to 100%. This study represents the first documented field evaluation in Kuwait's Burgan field demonstrating the successful application of low-concentration mud acid systems for sandstone matrix stimulation while preventing diagenetic alterations and permeability impairment. The treatment design integrates systematically optimized acid concentrations with a precisely engineered additives package to regulate acid-rock reaction kinetics and ensure mineralogical compatibility with formation lithology. This approach is specifically designed to enhance stimulation effectiveness while preserving near-wellbore formation integrity in mineralogically complex or permeability-sensitive sandstone intervals.