Are you encountering issues deploying the runtime or are you trying to deploy developer tools for an OpenCL™ application?
If you have any specific errors or questions please add them to this thread.
The link from JacekD has an install walkthrough for Intel® Graphics Compute Runtime for OpenCL™ Applications on an Ubuntu system.
To clarify OpenCL™ runtime options please take a look at this article.
Ubuntu 18.04 is deployed with a kernel newer than 4.11. Since that kernel the default i915 kernel module supports recent Intel® Graphics on Intel® Core™ i7 processors in NUC systems. So... applying runtimes per the github link should be enough to execute applications.