While it's possible to achieve on-target results using reliable and well documented operations, the current economic climate demands that newer, more cost-effective technologies are used to meet production targets and increase the profitability of drilling operations around the globe.
The Covid-19 pandemic, extreme weather events and declining production and have had a tumultuous effect on global oil prices, presenting enormous challenges to the industry.
It is a top priority of the oilfield equipment and services industry to continue to focus on reducing costs and improving efficiency. Thus, sustainability is strengthened all the way from drilling to decommissioning.
Fortunately, the last decade has shown rapid developments in frac design. Newer wells have been created with greater levels of proppant and fluid, better cluster spacing and longer lateral lengths, all of which has helped to increase production.
It could be that older wells, created using less up-to-date technologies, may have been under stimulated – leaving significant reserves of stranded oil that can be unlocked to boost production for a relatively small outlay.
To be clear, re-stimulation of mature wells are a very real alternative to drilling a brand new one. The estimated figure for creating and completing a new well, ranges from five to ten million US dollars, but refracturing can uncover reserves in an existing, mature horizontal well at a fraction of the cost. (25-50% according to research published by Well Data Labs) , allowing for leaner, more profitable operations that make good use of existing assets.
Re-stimulating an old well is faster too: Accelerating production and allowing you to meet targets without risking the many delays associated with drilling a brand new well.
How Are Stranded Reserves Unlocked In A Mature Well?
Thanks to rapid advancements in re-stimulation technology, it's relatively easy to unlock the untapped potential of a mature well by re-perforating casing in a productive zone, but there are challenges: Rock and casing failures are an ever-present threat, and you may need to close off older, unused perforations to maintain the integrity of a well.
To mitigate these problems, we've developed a unique, refrac casing patch called ReLine MNS. The latest in single-trip expandable technology, this advanced casing patch allows you to isolate problem areas , or seal unwanted perforations without significantly altering the ID of your well.
What Sets ReLine MNS Apart?
Before the advent of advanced expandable casing patches, operators had to rely on cement squeezes and synthetic rubber packers to re-implement the integrity, and increase the productivity, of a well.
Utilising ReLine MNS systems enables operators to repair the troubled area with minimal loss of tubular internal diameter. The system is deployed with higher-performing materials, and a unique frac sealing system, for applications requiring isolation from fracturing. This enables the system to handle high treating pressures, as well as the induced loads from high-temperature cool downs. Optimised production diameters are retained whilst achieving market leading burst and collapse ratings.
Loss of production is minimised, as wells critical to a project are quickly restored. This expandable casing patch is a versatile solution that can be deployed on jointed pipes of varying lengths with our longest installation to date, exceeding 7000ft Plus, it can be configured to expand and seal across internal diameter features such as frac sleeves or nipples. These modern technological solutions result in greater cost effectiveness and reliability and the return on investment is maximised.
We have installed over 300,000ft of expandable tubular patches in the market, with over 100,000ft used in horizontal sections for restimulation purposes. Relatively low capital investment has seen increased production and estimated maximised recovery of wells worldwide.
An operator tested four re-stimulation systems in an older well in New Mexico. The ReLine MNS's technology can leave the expanded liner in neutral while maintaining the speeds of expanding it using overpull. This unique feature results in the lowest operational cost. Post re-stimulation the original wells production was re-produced within in a 6-month period, and the forecasted estimated ultimate recovery tripled. The operator stated this would be their system of choice for other wells that required full-lateral restimulation.
Similarly, for a recent project in the greater Wattenberg field of the Denver-Julesburg basin, ReLine MNS's technology restored the pressure integrity wellbore to that of a new perforation. It is interesting to compare the two sites: the application and operational aspects were similar to that in New Mexico but the wellbore was smaller in this example. Production is lower from this type of well: the solution of an expandable liner with plug-and-perf was a good fit for this project. The recompletion results were maximised.
Proper Preparation Is Still Key
For optimal results to be achieved during refracing, well preparation and clean-out are essential. The efficiency and effectiveness of the wellbore clean-up phase can make a significant difference to the success of the recompletion. If this phase is carried out thoroughly, the expandable liner can be run to the intended depth and expand successfully.
As operators explore the possibility that refracturing could yield uncovered reserves in mature wells, so must the oilfield equipment and services industry support them in this sustainable activity. Alternatives to drilling new wells can be driven by utilising new technologies of which ReLine MNS system expandable casing patch is one. The case studies highlight the versatility of this innovative product and its success in restimulating well bores.