Oman completion strategies continue to evolve as more cased horizontal wells are completed. These wells must be perforated and, for the best production performance, should be completed underbalance avoiding any kill as part of the process. Early wells were perforated using coiled tubing with mechanical sealed ballistic connector 1 to shoot in underbalance conditions and retrieve the gun assembly without having to kill the well. While the use of Coiled Tubing is a very effective deployment method, the extreme trajectory of some wells requires that fluids to ease drag friction be pumped as part of the deployment process. These friction reducing fluids may damage the perforations resulting in poor productivity.A new wireline tractor conveyance technology designed for the harsh, high shock application of perforating has been used to perforate a long horizontal well section in underbalance conditions. Detailed pre-job planning and modeling was carried out to ensure the job could be executed as desired. Also the "lessons learned" gained in a previous attempt to use this technology helped improve the delivery efficiency. The guns were deployed and retrieved under controlled conditions minimizing any perforation damage in addition to significantly reducing the running times compared to other conveyance methods used in previous wells.Eighteen successful tractor runs were made deploying up to 18.9 m of 2 7/8" OD perforation guns per run shooting 253m of perforation interval. Operating time was reduced significantly compared to previous perforating operations and no additional formation damage was done to the perforations as part of the process. Subsequent well productivity was better than expected.The success of this operation opens up a wide range of applications for perforating or other heavy duty and high shock applications for this tractor technology. In the future different deployment technologies can be combined with the tractor for conveyance to push even longer gun strings into highly deviated wells in "live well" conditions further improving completion efficiency.This paper will review the technical considerations and the detailed planning exercise that is required for a successful tractor perforating job as well as the operational requirements to minimize nonproductive time (NPT). This in turn will improve job planning and the likelyhood of operational success for future perforating jobs in this complex operating environment.

This paper presents the design and implementation of a multichannel bio-impedance spectroscopy system on field programmable gate arrays (FPGA). The proposed system is capable of acquiring multiple signals from multiple bio-impedance sensors, process the data on the FPGA and store the final data in the on-board Memory. The system employs the Digital Automatic Balance Bridge (DABB) method to acquire data from biosensors. The DABB measures initial data of a known impedance to extrapolate the value of the impedance for the device under test. This method offers a simpler design because the balancing of the circuit is done digitally in the FPGA rather than using an external circuit. Calculations of the impedance values for the device under test were done in the processor. The final data is sent to an onboard Flash Memory to be stored for later access. The control unit handles the interfacing and the scheduling between these different modules (Processor, Flash Memory) as well as interfacing to multiple Balance Bridge and multiple biosensors. The system has been simulated successfully and has comparable performance to other FPGA based solutions. The system has a robust design that is capable of handling and interfacing input from multiple biosensors. Data processing and storage is also performed with minimal resources on the FPGA.

This paper presents the design and implementation of a multichannel bio-impedance spectroscopy system on field programmable gate arrays (FPGA). The proposed system is capable of acquiring multiple signals from multiple bio-impedance sensors, process the data on the FPGA and store the final data in the on-board Memory. The system employs the Digital Automatic Balance Bridge (DABB) method to acquire data from biosensors. The DABB measures initial data of a known impedance to extrapolate the value of the impedance for the device under test. This method offers a simpler design because the balancing of the circuit is done digitally in the FPGA rather than using an external circuit. Calculations of the impedance values for the device under test were done in the processor. The final data is sent to an onboard Flash Memory to be stored for later access. The control unit handles the interfacing and the scheduling between these different modules (Processor, Flash Memory) as well as interfacing to multiple Balance Bridge and multiple biosensors. The system has been simulated successfully and has comparable performance to other FPGA based solutions. The system has a robust design that is capable of handling and interfacing input from multiple biosensors. Data processing and storage is also performed with minimal resources on the FPGA.