Customer saves money & avoids risk in deep, Anadarko basin!
By Adam Swartley |
Tue, 1 May 2007
A major operator in Western Oklahoma recently used the SPIDR to perform a Pressure Build-up (PBU) on a 20,000í Springer well. The well had recently been brought on line and the operator wanted to perform a PBU in order to analyze the reservoir characteristics and see how effective the stimulation job was. In other words, did he have a negative skin which would indicate a stimulated completion?
Because this well was deep with a monobore 3 ?î completion, CO2 present, and a 275? F BHT with flowing wellhead pressures approaching 10,000 psi, the cost to run a downhole pressure gauge was substantial. In fact, the field operator described a potential cost in excess of $50,000 to rig up 15K iron and run-in for a short PBU, all because of the high activity levels in the area and a scarcity of 15K iron in the region.
The SPIDR Surface Well Testing System has been used by customers for over 22 years as a NO RISK and LOW COST alternative to running wire and pressure gauges in the hole for the purpose of Pressure Transient Analysis. If the Gas or Gas Condensate well flows and unloads produced liquids (if itís in Critical flow) without slugging at the wellhead, it is a candidate for the SPIDR system.
This well was shut-in for a little bit more than 2 days. One of the main advantages of testing from the wellhead is that the customer has real-time access to the pressure data and can track the progress of the test. Tracking the progress prevents the operator from keeping the well shut-in any longer than necessary to capture the pressure information. The customer initially thought that a 3 day PBU would be required but the data showed that 2 days of shut-in time was sufficient.
The customer found out that he did indeed have a negative skin with a higher permeability than he had originally estimated.
The total cost to the customer for using the SPIDR System was a little over $3,000. This includes rental of the SPIDR gauge, roundtrip transportation of the SPIDR gauge, conversion of the pressure data to BHP and the analysis for skin, permeability and P*. This cost represents approximately 6 % of the estimated $50,000 cost to run equipment downhole, without even considering the inherent risk of running wire and gauges to this depth in a new well!
