Advanced Combination of Proppant Fracturing and Sand Control Completion System Unlocks Gas Potential of Unconsolidated Jauf Formation in Bahrain

Abstract

The Jauf formation of Bahrain's Awali brownfield is currently underdeveloped due to an extremely challenging geological environment. Because of high heterogeneity, the formation requires fracturing to produce economically. However, the Jauf sandstone is unconsolidated, and formation sand production does not allow for high gas rates. A combined solution was introduced using a completion assembly with frac ports and screens to restrict sand production with a tip screenout approach in the stimulation stage. The studied well was completed with a 4 1/2-in. cemented liner that had been plugged and abandoned and left with 7 5/8-in. casing across the prolific Jauf sandstone. A completion string with screens and production sleeves, fracturing ports, and packers was deployed to compartmentalize and fracture the Jauf. Fracturing ports, while production sleeves were later manipulated with coiled tubing (CT) to allow production across the sleeve filter media, thereby preventing proppant or formation sand from being produced. A large fracturing treatment was placed in an aggressive tip-screenout mode to achieve optimum fracture length and maximize fracture conductivity. Afterwards, CT was used to close the fracturing port and open the screen ports to flow back the well and proceed with testing operations. A hydraulically activated shifting tool was used to manipulate the fracturing ports (open and closed) as well as the production ports enabling gas production through the included screens. This technology enabled the fracturing operation to be executed in conjunction with sand management hardware during production, further providing more flexibility for future intervention operations when compared to frac-and-pack type assemblies. Considering the significant depth of the formation (11,700 ft), degradable fibers were used to minimize friction pressure and, respectively, maximize fracturing treatment rate to allow for optimum height coverage and lateral fracture penetration. The post-stimulation sand-free gas production rate through the screens was greater than 20 Mscf, which was confirmed with choke-variability testing operations conducted after manipulation of the completion ports. The trial well proved that proppant fracturing combined with innovative sand control hardware provides an effective method for producing gas from the prolific Jauf reservoir. The described completion system represents an alternative to a traditional frac-and-pack hardware solution, enabling full control of the well with CT interventions. A tailored stimulation design and advanced placement technique coupled with detailed description of completion design and operations sequence will be of interest to experts dealing with tight unconsolidated formations in the Middle East and other regions.

A critical review on analysis of sand producing and sand-control technologies for oil well in oilfields

“…With the continuous innovative progress of sand control technology, a variety of sand control technology has been formed. Among them, the conventional sand control technology mainly includes mechanical sand control, chemical sand control, coking sand control and composite sand control (Nie,S et al, 2023;Ma,L et al, 2022;Prasad V et al, 2020). Mechanical sand control techniques mainly use slotted liner, wire-wound screen and gravel pack to prevent formation sand bodies from entering the well bore (Matanović et al, 2012;Rodoplu R S and Al-Mohanna K S, 2019;Rozlan M R et al, 2022).…”