D65: Resources Applications for Oil and Gas Reservoirs

Planning a Section 4.2 application for Acid Gas Disposal? Bottomhole injection pressure, maximum sandface (reservoir) pressure, caprock threshold pressure, fracture propagation pressure, and formation fracture pressure estimates are all required. It is not desirable for acid gas disposal wells to exceed the formation fracture pressure because of possible isolation problems. We recommend a Mini-Frac’ (#DFIT) and Fall-off test, conducted with subsurface pressure recorders (over a Step-Rate test) to optimize your maximum wellhead injection...

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Welltest 106: Impulse & Closed Chamber Tests

Welltest 106: Impulse & Closed Chamber Tests

Surface Data Recorders Modernize Underutilized Techniques. Impulse testing has been around for some time and analytical theory is well documented. Modern electronic surface data acquisition equipment has made impulse testing practical and economic in the Western Canada Sedimentary Basin. Issues advancing usage include under-balanced perforating, coiled tubing frac’s, by-passed pay, ultimate recovery in low deliverability systems, flaring, confidentiality, and general exploitation. Order-of-magnitude reservoir flow characteristics (kh, s,...

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Welltest 104: Surface Data Acquisition

Welltest 104: Surface Data Acquisition

Valid interference #welltest results can be obtained from water injection wells, flowing oil wells, and pumping oil wells. For this example, pressure buildup data were obtained on a pumping oil well using both an acoustic well sounder and an electronic surface pressure recorder. There was no obvious indication of interference from the #AWS data set which, by nature, was quite sparse. Surface annular (casing) pressure data, on the other hand, clearly exhibited a pseudo steady-state relationship through the late-time region, identifying...

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Welltest 104: Surface Data Acquisition

Welltest 104: Surface Data Acquisition

It appears only logical that surface pressure data could prove useful for interference #welltesting in high permeability gas zones. Valid results have been derived from both producing wells and injection wells. This example illustrates the surface pressure data trace from a gas (#LNG) storage observation well. Subsurface pressures exhibited identical behaviour. Substantial cost savings were realized with future #welltest operations by not requiring expensive electric wireline services for surface readout of bottomhole pressure gauges....

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Welltest 104: Surface Data Acquisition

Welltest 104: Surface Data Acquisition

Perforation Inflow Distribution Diagnostic (#PID) #welltests can differentiate inflow ratios in multi-layer completions. By perforating subsequently better layers, an increase in surface pressure buildup slope is equal to an increase in gas inflow. It may be necessary to blow down the wellbore to maintain critical flow conditions across the perforations. Analytical results are analogues to production logging surveys and can be utilized for identifying movable gas, proving recoverable reserves, determining log cut-off values, or identifying...

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