For the first time in the region, a multistage fracturing completion technology that enables simultaneous fracturing and controlled sand production was successfully installed. After the fracturing operation was conducted through frac ports in multiple zones, coiled tubing (CT) intervention was needed to shift the frac ports closed and then open the production sleeves located within the sand screens. It was necessary to use the appropriate shifting tools and utilize the downhole parameters to ensure the shifting operation success. CT was first utilized to mill the frac balls and associated seats after the fracturing operation, and this was followed by CT intervention to close the frac ports and open the sand control production sleeve. CT providing real-time downhole parameters was utilized during the shifting operation as its downhole weight provided the ability to apply required surface forces to shift the respective well accessories. Additional benefits were gained by utilizing the depth correction and obtaining the required differential pressure across the shifting tool in real-time ensuring tool functionality at optimum parameters. The success of the innovative multistage completion operability depended on the successful implementation of shifting operations to close the frac ports and open the production sleeves with sand screens. Therefore, it was very important to select and deploy the appropriate shifting tools that can be trusted to actuate each of the respective well accessories. A series of yard tests were conducted to understand the hydraulically operated shifting tools. After the successful yard tests, during the design phase, each of the shifting operation steps were elaborated with the respective contingencies, and it was confirmed that the CT equipment utilized for the job can provide the required surface and downhole weights. The hydraulically activated shifting tools operation during the actual CT intervention was optimized using the CT by providing real-time downhole measurements of depth correction, tension, compression and pressures. The downhole measurements helped in repeating the shifting step as needed and helped in confirming that the respective well accessory is shifted. During the intervention, two frac ports were shifted close. Whereas, there were two production sleeves with screens shifted open. The use of the two different hydraulically activated shifting tools during the shifting operations for the first successful multistage fracturing with sand control completion system will be detailed. The paper also describes the full benefits of monitoring downhole parameters during shifting operations enabling the tools to operate at optimum conditions and ensuring the shifting is conducted successfully.

Different approaches and techniques were utilized in the industry to overcome challenges in sanding formations, including frac-packs, indirect fracturing, and resin coated proppants. Due to complexities in the results achieved, open hole multistage fracturing (OH MSF) with a sand control completion system was introduced with the goal of expanding the technology portfolio for controlling sand production and proppant flowback. Offset wells drilled in a prolific gas-bearing unconsolidated sandstone formation showed high sand and proppant production restricting the potential from these wells. Therefore, it was necessary to develop a new OH MSF completion strategy to address sand/proppant control and combine it with proppant fracturing at the same time. This paper highlights OH MSF technology that utilizes screened port sleeves capable of withstanding fracturing pressures and harsh environments. The new completion system consists of a hydraulic frac port opened by applying pressure in the first stage. In addition, the fracturing ports for the next stages are opened by dropping activation balls. Each stage needs to be equipped with a sleeve fused with a screen for sand and/or proppant control. Stages are separated by open hole packers for zonal isolation in the open hole section. It is an innovative system that combines MSF completion with sand control components. Due to the complex nature of the completion, rigless well intervention operations must be well planned, discussed, and conducted with close monitoring during all the operations. In particular, frac port opening/closing, sand screened sleeves opening with coiled tubing (CT) well interventions, proppant fracturing operations, and e-line production logging tools (PLTs). Besides, if the transmissibility is high with a high leak off and quick closure of fracture, then frac operations should be performed with the objective of creating a tip screen out (TSO) scenario to achieve good proppant packing close to the wellbore area. Production rates after completing proppant fracturing, CT milling, and shifting interventions exceeded the expectations without any sand or proppant flowback. The candidate well's rate remained higher than offset wells and no sand nor proppant were observed on the surface. The new OH MSF with sand control completion technology will enable performing OH MSF treatments in gas formations with a high sanding tendency. In addition, it helps to diversify technologies utilized to enhance production without producing formation sand or proppant. Utilization in the right candidate in conjunction with an optimum engineering approach and optimized design will ensure obtaining the benefits of this new completion system to overcome similar challenges.

Acid stimulation and fracturing in multiple layers formation requires an integrated approach to design and execute an effective stimulation treatment. An extensive campaign of acid stimulation on carbonate formation to increase productivity index in a deep High Pressure High Temperature (HPHT) gas bearing carbonate formation is discussed here. A high degree variation in permeability across long interval, stress barriers between target zones, and completion limitations were main challenges to design an effective stimulation treatment. The target was to achieve effective acid stimulation for multi-layers carbonate formation with different formation properties and stress barriers. Although all layers had similar initial pressures and gas compositions; but different properties. Comingled flow was planned from the formation, therefore effective stimulation for each layer was recommended to drain effectively and improve recovery. To assess the best stimulation strategy in early stage of development, complete set of diagnostics conducted across all formations before and after the acid treatment coupled with geomechanical studies on actual core samples. Various stimulation techniques were implemented from Small Matrix Treatments (SMT) with Coiled Tubing, Matrix Acidizing Treatments (MAT), High Rate Matrix Acidizing (HRMA), and Acid Fracturing Treatment (AFT). Thorough study of results as part of learning process was conducted to optimize the important parameters that affect the stimulation efficiency such as perforation strategy, completion design, diverter selection, fracturing design and implementation. The importance of modeling in optimization process, comparison between different treatment types and fluid systems is discussed supported by actual data such as temperature logs, post-treatment flowback analysis, pressure transient analysis and production logging results.

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15K Open Hole Multi Stage Fracturing (OH MSF) completion was successfully implemented with the goal of hydrocarbon production at sustained rates from tight HPHT gas formation and to diversify technology portfolio to address similar challenges. OH MSF completion technology has been globally proven successful in enhancing the well design, stimulation efficiency and production. As more wells are being drilled deeper, longer and in more challenging formations, the OH MSF technology also evolved resulting in introduction of a HPHT – 15K psi working pressure - MSF system. The technology had to overcome many challenges before it could be deployed. Pre-deployment stages of this technology have two main components;Standard tool design including material selection, NACE compatibility, dimensions, API standard compliance, testing, and prototypingCompletion construction design, installation challenges & force analysis The candidate well was drilled horizontally to achieve enough formation contact in a tight HPHT formation. Wells with similar poor development have been seen to require upwards of current OH MSF completions reaching to their limits of 10K psi differential pressure downhole to successfully complete with proppant fracturing. Candidate well was planned to be trial tested with 15K OH MSF completion to solve the challenge of high breakdown pressures and to capitalize on the greater productivity of open hole completions across this tight HPHT formation. The proppant fracturing operations resulted in the successful completion of five stages of proppant fracturing in this formation. A total of more than 1.2 million lbs of proppant was placed during hydraulic fracturing operations exceeding 10K differential pressure across the MSF completion. The well showed an excellent post frac flowback results exceeding expectations. Previous wellbore completion pressure limitations in many instances acted as a constraint to reach job objectives has been surmounted. The implementation of 15K OH MSF completion system has helped pave the way to attend tighter formations in an efficient and cost effective manner. Engineering approach and design to develop this completion system and utilization in the right candidate confirmed the benefit of the completion for field development options. The implementation of this technology will improve and diversify the efforts in exploiting tight HPHT formations.