At the recent Unconventional Resources Technical Conference in Denver, a direct measurement of what is downhole was a theme of new products offered to operators who see the need for more data on what is working, what is not working, and what could be made to work better.
The offerings had to strike a balance between gathering better data downhole and doing so at a price in line with the cost limits of companies grinding out profits by drilling hundreds of wells.
And both are arriving at a time when multiwell pad sites are increasingly the focus of development. These clusters of wells reduce the space, time, and cost associated with completing multiple wells.
One wants to consolidate more formation testing on site, and the other wants to sell data revealing how tightly spaced wells interact.
While rolling out a tool for collecting cores and preserving their fluids, Don Westacott, chief adviser of global unconventional reservoirs at Halliburton, said the company is working on a new well-side testing service to guide development on pad sites that it expects to roll out early next year.
A new tool from Baker Hughes will provide pressure and temperature data which, among other things, will allow decision makers to see if fractures from nearby wells or stages connect, creating communication that may or may not be a positive development. The data gathered is not new, but this is designed to do so at a lower cost.
“They wanted fracture and early production monitoring, but at a lower cost,” said Thomas Scott, production line manager of well monitoring systems at Baker Hughes.
Putting a Lid on It
A new coring device from Halliburton took a tool that has been used to collect multiple sidewall cores and put a lid on it.
The new system is called CoreVault because it seals in up to 10 sidewall core samples to prevent volatile fluids from being lost in transit. Those can be from 50% to 70% of the hydrocarbons present, according to the company. “The most important part of a reservoir was exiting that rock and going into the air,” Westacott said.
To make up for the loss, laboratory results are commonly adjusted based on the rule of thumb that more than half of the hydrocarbons in place are lost when estimating the productive potential of the rock, he said.
But Westacott said direct measures of collected sidewall cores from unconventional reservoirs showed the actual losses were sometimes more than twice the estimates from labs, which adjust for expected losses. “We are not extrapolating, we are measuring,” he said.
In a field test, samples gathered using the system measured two to five times as much gas in the rock than standard testing, and the cores pointed to locations with higher organic content.
To limit product development cost, the new device added a closable seal to a proven downhole core collection device, thus limiting the development cost and marrying it with one that has been proven.
Multiple Looks
Tightly spaced well development offers opportunities to lower cost and increase production while fracturing, but the fractures created are not always as planned.
Baker Hughes rolled out a new tool called StageWatch, with instruments mounted in a sleeve that fits inside the casing to gather pressure and temperature data at designated spots in the well without complicating well completions.
The same could be said for fiber-optic cable, which can offer data on a meter-by-meter basis, but at a cost that limits the number of onshore wells that fits into the budget. The goal of StageWatch is to gather data for less.
Each sleeve includes two gauges and is designed to not interfere with fracturing. It stores data for later retrieval, downloading, and analysis. It is designed to be mounted in a casing joint so it can be installed with the casing and retrieved later by using coiled tubing.
The data gathered can be used to detect communication between wells or stages, as well as characterizing the fractures created by the stages, Scott said. “One thing that is eminently clear with the rise in pad drilling is there is more interwell communication,” he said.
Other possible uses are to tell which sections are producing effectively and to do early production monitoring.
While the name was chosen with the idea of installing the device with every fracture stage, Scott said feedback suggested that customers would likely install three in the lateral, with one at each end and one in the middle.
Baker Hughes is working on ways to expand what insights can be extracted to help manage future work. The hardware built to operate at pressures of more than 15,000 psi and temperatures as high as 150°C is likely be paired with analysis.
