What's new in production

Your colleagues down the hall in marketing may have their eccentricities, but give them credit for this: their Paleomarketing ancestors invented the trade show, a pleasant way to take in new tech, and to discuss it with knowledgeable people.

A case in point is SPE’s annual hydraulic fracturing conference. As before, on display at its most recent manifestation were many interesting ideas worth your attention. Space allows only a few to be cited here as unranked examples.

Injection system combination. An injection system from NCS Multistage combines regulated injection sleeves with hydraulically actuated zone-isolation packers, deployed on production tubing, for installation in existing production casing. Unlike bullhead injection or conventional injection-control devices (ICDs), this system allows individual zone injection to be adjusted via wireline- or coiled-tubing-deployed tools to maintain overall sweep effectiveness. It is compatible with CO2 injection and is suitable for both horizontal and vertical wells.

The company says the system enables individual zone injectivity and injection profile management to balance flowrates along the wellbore. Reduced efficiency loss, due to short-circuit breakthroughs and thief zones, is also claimed, as well as mitigation of injectivity loss, due to plugging, erosion, corrosion and scale.

The system is deployed on production tubing inside existing production casing. Injection sleeves are shifted, using standard B shifting tools deployed on coiled tubing or wireline.

Injection flow control is provided by a proprietary regulator, a calibrated tortuous path that induces back pressure without relying on small-diameter orifices or nozzles that are prone to erosion and plugging. An integral screen prevents larger particles from entering and obstructing the flow path (fines will not cause plugging).

Dual regulators in each sleeve provide redundancy or allow alternate injection rates to be selected. Multiple sleeves can be installed in a zone to enhance injection control capability. Non-regulated, open/close sleeves can be installed in tandem with regulated flow injector sleeves to provide higher injection capacity, when needed, for fill-up, evaluating injection index, or acid treatment. The entire injection string is full tubing drift to accommodate production logging and fiber optic tools.

Micro-proppant for micro-darcy rock. A microproppant developed by Zeeospheres to optimize reservoir recovery and mitigate steep production declines targets the reservoir’s secondary fracture network—specifically, those fractures too small to accept conventionally sized proppants. The material’s high crush resistance (60,000 psi) allows it to maintain conductivity at very high closures.

The company says that its microproppant has proven most effective in shale formations, with a Young’s modulus of 2.5 million or greater, and a permeability of less than 5,000 nano darcies, and notes that most of the major shale plays across the U.S. fit these characteristics. When applied in these formations, reserves can be recovered earlier and for a longer period of time, which ultimately increases total recovery from the well.

Work by Dharmendra, Gonzales and Ghassemi at the University of Oklahoma indicates that an additional 1,500 m2 (16,000 ft2) of fracture area in the Eagle Ford shale and 818 m2 (8,880 ft2) in the Utica shale can be propped with the company’s microproppant, compared to 100-mesh sand.

A view from within. A downhole, array sideview camera—developer EV says it’s the world’s first—provides a continuous 360° view of the ID of the wellbore. This enables the creation of a 360° dynamic map of well condition and behavior, from the lubricator to the toe of the well, in a single, continuous run in hole.

An array of azimuthally aligned cameras captures four, high-definition, high frame-rate video feeds and combines them to create an infinitely long, continuous image of the well. The company says a down-view video sensor can be added for a complete perspective of downhole conditions.

Yes, it’s dark down there, but the camera’s lighting system is said to provide spatial differentiation and image clarity in poor fluid conditions. The image examples on display certainly demonstrated that claim.

The system provides a switchable, real-time view from any of the four array cameras or down-view camera. A high-capacity memory module provides the capability to record all four array cameras simultaneously, to capture a complete map of the internal tubular surfaces and flowing phases, while operating at standard logging speeds.

A through wire enables “passenger” operations. This increases integration capabilities, with applications such as well integrity and production logging evaluation, and real-time feedback for mechanical services, such as cutters or valve/sleeve shifting tools.

The company says, and this certainly makes intuitive sense, that the combination of video with conventional data sources increases the value of the derived information, reducing assumptions and increasing the accuracy of analysis and interpretation products.

“Mosaicing” is the awkward anthimeria that the company uses to describe its process of creating a continuous image of the downhole environment. The stitched images of the complete wellbore have a data resolution of 16 pixels per square millimeter, when running at 30 ft per minute. A patented motion-computation algorithm enables determination of downhole depth by direct measurements acquired from the bottom hole assembly. This enables speed correction of video data, placing each pixel on depth within the well, and by extension, any log data that are recorded simultaneously in the same pass.