An LNG plant in Australia was designed to maximize energy efficiency and minimize greenhouse gas emissions. In steady-state operations, its greenhouse gas emissions are lower than any in-country LNG project. Typically, gas supplied from two offshore fields contains CO2 (~14%) and high-volume operations run smoothly. At the time of this project, an injector well was found to have critically high CO2 levels (99%), and two other injector wells were shut-in due to pressure anomalies. A solution was needed to confirm casing isolation and detect leakage, while maintaining well barrier integrity and monitoring pressure/temperature below the tubing hanger plug. An innovative acoustic transmission platform served as a barrier assurance tool. A transmitter module (below the plug) has pressure/temperature sensors sending data through tubular/casing walls. A receiver module (above the plug) also houses pressure/temperature sensors. Once configured and deployed downhole, barrier installation is recorded, and barrier setting is verified before pressure testing. During the pressure test, sensors record pressure/temperature (in Wireline mode or fed live to surface) from either side of the barrier, confirming its integrity. The integrated wireless barrier monitoring solution exceeded customer expectations, with continuous acoustic and wireless communication maintained throughout the entire operation. Simultaneous monitoring of two wells for 500+ hours accurately documented the barrier integrity via pressure testing results. The system was run downhole in conjunction with a non-explosive slickline setting tool and retrievable bridge plug allowing to not only log the setting sequence for quality assurance but also record the pressure & temperature across the barrier. Conducted on-location, the customer was able to witness the plugs being successfully set. They then received positive confirmation of established well barrier, by continuous monitoring of the pressure between the two barriers and interpreting data from the wireless system in real time. This combined technology approach reduces time to troubleshoot and verify barriers, enabling quick evaluation of the leak source. Other benefits include significant time savings over traditional isolation methods, improving personnel safety in the well bay area by conducting real-time diagnostics, while also optimizing the suspension to allow efficient intervention or abandonment operations. The main objective of the operation was met, and verification of the shallow set plug was achieved. Barrier verification without the acoustic real-time wireless system would have been questionable. During well intervention for a major LNG plant operator in Western Australia, the novel wireless barrier monitoring solution delivered efficient, real-time pressure testing and verification to ensure success. This marks the first global installation of an integrated barrier system, combining retrievable bridge plug with wireless acoustic telemetry in supercritical CO2 disposal well. It not only allows a shallow bridge plug to be verified as a leak-free barrier, but it also enables efficient evaluation of the entire well barrier envelope.

An Operator wanted to perform a Drill Stem Test (DST) using wireless Surface Read Out (SRO) and downhole sampling of a deep wildcat exploration well (∼4200 mMD) with limited reference from adjacent wells. This first high-pressure, high-temperature (HPHT) exploration well to be attempted in the area was particularly challenging, because it lay in a swamp and had to be drilled with a swamp rig. Immediate, fast decisions would be needed during the DST operation. To ensure accurate DST results in this deep, HPHT well with challenging swampy conditions and lack of adjacent well data, Company deployed its newest wireless acoustic telemetry SRO system, in conjunction with the latest generation tubing-conveyed bottomhole sampling system. A globally proven DST tool string was configured with a retrievable cased hole packer, tubing string testing valve, downhole tester valve, multi-cycle circulating valve, and single-shot rupture disk circulating valve. This innovative solution was engineered to meet the Operator's requirement for reliable, real-time downhole data and representative bottomhole samples of the well. The DST system delivered results was met the Operator's expectation, with successful execution and acquisition of all requested downhole data despite interference from well intervention activity, and collection of all bottomhole samples although killing pressure exceeded the original plan. The wireless SRO system, rated up to 20K psi and 350° F (177°C), allowed the Operator to monitor and analyze real-time bottomhole pressure (BHP) and bottomhole temperature (BHT) for quick decision-making while receiving continuous assurance of downhole tool status. The modular concept supports efficient preparation and testing of tools offline, so risk can be reduced compared to other systems available that can only be tested online (on the rig floor before running in hole). The tubing-conveyed bottomhole sampling system captures more bottomhole samples (9x 400c) than traditional, slickline-conveyed sampling (2-3x 600cc in one run). It also minimizes risk as no well intervention is required and does not add additional time to DST operations. The annulus-pressure-activated bottomhole sampling system incorporated enhancements to upgrade internal sampler tubing pressure from 12k to 15k psi. These enhancements enabled higher well kill pressure for more flexibility, without risk to captured samples. This combined solution provided ongoing reservoir insights that enhanced decision-making, avoided wasted rig time (saving 36 hours), and led to significant cost savings. The wireless SRO system increased confidence in well kill operations, due to observation of actual BHP at surface in real time. The tubing-conveyed bottomhole sampling process worked successfully, without losing the contents of any samplers, even with higher than planned well kill pressure. Overall performance improved compared to slickline-conveyed bottomhole sampling runs.