Vx Technology Provides Well Testing Efficiency and Rig Time Savings
Published: 09/01/2009
Vx Technology Provides Well Testing Efficiency and Rig Time Savings
Published: 09/01/2009
Optimize well testing and cleanup monitoring and minimize rig footprint
Shell implemented a simultaneous operations (SIMOPS) strategy whereby drilling and completions were conducted at the same time as the stimulation, perforating, and cleanup for the North field production operations feeding Pearl GTL, a project under development by Qatar Petroleum and Shell in Qatar.
The highly successful SIMOPS approach reduced the average overall rig time to deliver a well for production from 76 d to 45 d. One requirement in accomplishing this 40% reduction in rig time was a significantly reduced footprint for well testing operations.
Deploy PhaseTester equipment to test the wells and confirm cleanup before putting them on production
Shell elected to use PhaseTester portable multiphase well testing equipment with Vx technology to reduce the well testing operations footprint, improve safety, and achieve operational flexibility when acquiring high-frequency measurements of produced gas and completion fluids.
ArchiTest* well test design and methodology software was used to design the 10,000-psi system, which featured flanged connections and flare-boom lines rated for flow rates to 120 MMcf/d. Continuous measurements ensured that the velocities in the line remained within design limits.
Clean up, test, and switch to production immediately upon confirmation of cleanup
The wells were cleaned up and tested at gas rates above 100 MMcf/d. Flow at such high rates improved the cleanup of the wells and perforation tunnels.
All fluids were flowed through PhaseTester equipment from initial cleanup. The instantaneous and cumulative brine and spent acid production rates were measured continuously with PhaseTester equipment, making it possible to quantify the efficiency of cleanup operations from the first opening of the wells and assist in the evaluation of formation damage caused by residual stimulation fluids. The well effluents were sent directly from the flowmeter to the flare without separation.
PhaseTester equpiment used for the tests was rated to working conditions of 7,500 psi [51.7 MPa] and 302 degF [150 degC]. The Vx technology incorporated in the flowmeter converted the volumetric flow rate calculation in the HPHT operating conditions to standard conditions and emulated the two-stage separation Shell had in place. As a result, the dynamic response of the flowmeter made it possible to quickly estimate the performance of the gas wells, even during choke changes. Quick surface performance analyses from multirate gas tests provided good estimates of well performance and deliverability.
Additionally, accurate monitoring of the basic sediment and water allowed the well to be switched to production with certainty that it had been cleaned. Early routing to the production line saved hydrocarbons and reduced emissions.
Compared with traditional test separators, the PhaseTester equipment improved safety by eliminating the need for pressurized vessels on the platform and by reducing the number of field personnel required.
Challenge: Measure gas rate and monitor fluid returns from initial well opening; minimize rig-up time and the footprint on the platform; keep deck loading under 1.74 psi; estimate well deliverability from surface data; and enable safer operations with a smaller crew
Solution: Use PhaseTester portable multiphase well testing equipment with Vx† technology for continuous measurements of instantaneous and cumulative flow at high gas rates and to minimize the rig space required
Result: Conducted test confirming cleanup as soon as it was accomplished, providing good estimates of well deliverability and improving operational safety
