With drilling and completion activity forecast to grow by a 4% compound annual growth rate until 2020 and some 72,000 wells estimated to be completed by the end of 2019, well intervention activity is set to rise. Indeed, the latest global well completion and intervention expenditure is expected to reach $79 billion for onshore and $13 billion for offshore this year, according to a November 2018 Rystad Technology Oilfield Service report.
For most operators, well integrity and production optimization remain the key drivers in the planning of well intervention activity. To help make these vital decisions, they look to the service industry to develop tools that bring sensory capabilities and assist in understanding the well conditions. This includes visual, acoustic and, in certain cases, the thickness of wellbore casings and tubing. A key enabler for visualizing this is camera technology, captured in real time or memory, using HP/HT tools deployed on wireline.
These techniques have reached a point where the industry can use 3-D headsets to visualize the well and identify the problem, including the capability to measure and gauge the size of fishing necks on stuck tools, hole sizes for perforations and the nature of debris and scales.
This technology is critically important for well intervention activity as it provides a clear understanding of the (previously unknown) wellbore. The camera and video technology can be deployed in a wide range of operations, including casing and well integrity monitoring, downhole inspection, operational verification and production monitoring for both on and offshore wells globally.
The data gathered then allow decisions to be made on location, helping reduce downtime and cost, while ensuring remediation solutions are delivered quickly and efficiently.
Fracturing applications
One of Expro’s North America clients leveraged this technology to support a recent hydraulic fracturing campaign to avoid leaving hydrocarbons stranded, particularly in zones with smaller perforations. The camera was used to identify and measure the entrance hole size while understanding the position of perforations in its 5.5-in. casing. The operator needed to deliver this in a cost- and timeefficient manner, avoiding traditional methods such as electric line with tractor or e-coil conveyance.
On this basis, a Vision WellCAM system and WellViewer software with an image measurement feature were deployed to understand which zones had received the initial fracturing treatment, while identifying areas of focus for a second fracturing operation. A single camera string visually logged the well in one seamless, high-resolution color image, harnessing the 360-degree horizontally and 180-degree vertically panand- tilt capability. This allowed complete side and downhole viewing in memory and e-line mode, supported by a large internal 128-GB storage capacity that provided 24 hours of continuous recording.
Using measurements as little as 1 mm, the operator successfully discovered oversized perforations in the areas that had received the frac sand, which resulted in erosion from flow through the perforations. The full campaign inspected more than 700 perforations, with the largest variations in perforation size being .5 in. by .9 in., .58 in by .79 in. and .26 in. by .41 in.
This allowed the client to understand the results of its perforating program better, allowing it to plan a more productive second campaign, saving more than $100,000 and about two days of rig time compared to standard coiled tubing.
Geothermal applications
Downhole video cameras also are being used for hightemperature geothermal applications, where caliper and camera services are routinely performed as part of the well surveillance program worldwide.
On one particular project in which a client required to run routine pressure and temperature logging in its geothermal well, the existing service company was unable to retrieve the logging tools. Also, the temperature of the well was more than 148 C (300 F), posing additional technical challenges.
Assuming there was a casing integrity issue in the well, the client sought an alternative solution to running gauge rings or a caliper log.
Expro was approached to deploy its high-temperature (up to 176 C [350 F]) downhole video camera, which confirmed the parted 133?8-in. casing was causing rock and cement to enter the wellbore and trapping the logging tools downhole. Running additional tools could have been potentially caught in the split casing and either damaged the casing or become deemed irretrievable.
By helping to inform decision-making, this saved 12 hours of rig time and two separate runs in the hole. Visualization of the parted casing provided detailed images of the rock and cement that entered the casing, allowing the most cost-effective remedial solution to be implemented.
The client now routinely deploys downhole video cameras within its maintenance program up to twice a year to monitor the effects of corrosive fluids in these geothermal wells. This proactive approach avoids well integrity issues and associated costly repairs, saving up to $1.5 million to repair the well or $5 million to cement the well.
New technology developments
In addition to using video and camera technology to monitor wellbore conditions, operators can use a combined camera and caliper system, providing a more accurate representation of wellbore conditions. The combined caliper and video string, CalVid, allows wellbores to be measured and visualized at the same time, giving operators a complete understanding of the wellbore. Critical decisions regarding well and production integrity can be made based on a complete and accurate assessment of the entire wellbore, minimizing separate runs and rig time.
Working in partnership with Expro’s camera services partner, Vision iO, both companies are enhancing the technical capability. One such development includes cameras that can visualize the downhole environment in a 3-D view that will enhance the information provided from down the well back to the surface.
As the well intervention market continues to grow this year and onward, and as the need to receive information in real time increases, operators are looking for innovative and advanced technology options to ensure they can make decisions quickly. Utilizing video and camera technology can help drive the decision-making process, allowing operators to save both time and costs, ensuring remediation solutions are delivered quickly and efficiently.
石油圈
