H&P spearheads collaborative effort on standardized API schema for RSS downlinking

Standardizing rotary steerable system (RSS) downlinking, or the process of sending directional steering commands from the surface to RSS tools downhole, can be a huge step in optimizing directional drilling. A universal standard can allow third-party directional drilling providers, rig control systems and LWD/MWD toolmakers to interface smoothly, reducing nonproductive time on the rig by reducing misinterpretations between systems.

Over the past year, H&P has developed a standard application programming interface (API) schema for RSS downlink communication to enable third-party directional drilling providers to send commands directly to rig control systems. This schema, which was developed in consultation with Halliburton and SLB, provides a common language for the RSS tools to communicate with the rig, reducing potential errors in command transmission and minimizing failed downlinks.

The API schema acts as the blueprint for downlinking to RSS tools. It defines the structured data format used to send steering and operational commands – such as target toolface, inclination or flowrate encoding parameters – from surface advisory software through the rig control system to downhole tools. The schema acts as an instruction manual of sorts, detailing exactly what parameters can pass through an API. It ensures that both the sender (the surface tools) and the receiver (the downhole tools) process information exactly as expected.

Currently, there is no single universal API schema dedicated to RSS downlinking. Instead, the industry relies on various standards, combined with proprietary APIs provided by directional drilling and rig automation vendors for surface-to-downhole command validation. The H&P schema, which has been used on H&P rigs running with SLB or Halliburton RSS tools since February 2025, creates a common, secure protocol so that different third-party RSS providers can interface with the company’s rig automation infrastructure. It was released to the Drilling and Wells Interoperability Standards (D-WIS) workgroup for wider industry use on 28 July.

“What we realized is that it’s so much more complex if we have different schemas for different service companies,” said Todd Fox, VP of Technology and Engineering at Bentec, a sister company to H&P, and one of the key drivers of the standardization initiative. Mr Fox worked on this initiative while in a previous role at H&P.

“We’ve got a schema now that is very reliable with Halliburton and SLB tools, and we’re looking to take that schema and make it available for third-party rental RSS tools and other RSS tool providers outside of Halliburton and SLB. We want it available to any other RSS provider that wants to use that schema.”

The API is installed within the rig’s control system, linking the surface tools with the RSS tools. The surface tools feed information to the rig control system – this can include things like the directional tendency requested of the downhole assembly, or the core directional vectors required to update a well path. The rig then analyzes that schema and executes it accordingly, passing the information along to the RSS tools.

Mr Fox described the interaction of the schema and the surface tools as that of two Morse Code operators: “They both have the same language, and they both have a way to know the other one heard the message. It’s really about how the schema is set up. The message may be very different. It may be ‘See Spot run’ or it may be ‘The firehouse is painted red.’ It’s a completely different message, but it’s in a digestible format, and it’s validated that each party both received and understood the message.”

Part of the standardization initiative involved the development of a standard cybersecurity check through which H&P and the RSS tool provider could siphon information traveling from surface to downhole.

“We spent a lot of time on the cybersecurity element, making sure that we had that cyber-secure link to the rig,” Mr Fox said. “When you’re looking at a system that can directly control our rig equipment, you need a layer of oversight that you have to feel very good about. It needs to be a robust cyber-secure link.”

H&P began developing the schema jointly with Halliburton and SLB in 2024. In late 2024, the companies began testing on H&P’s simulator in Tulsa, Oklahoma, which was followed by live testing on H&P’s R&D rig in Tulsa. First testing on an active rig took place in February 2025.

The schema was then made commercially available for H&P rigs running with SLB and Halliburton RSS tools in October 2025.

“We knew from the beginning that we needed a neutral third party to publish this information,” Mr Fox said. “If we can all agree to use the same schema, we’ll make that schema public through D-WIS. That way, if any other provider wants to use the same schema on their end, they can. It doesn’t matter if it’s an H&P rig or not.”

Mr Fox added that he hopes publishing a standard schema through an industry group D-WIS will encourage other drillers and OFS providers to publish their own schemas, enabling greater interoperability within systems.

“In a perfect world, we wouldn’t be the only ones providing schemas to D-WIS,” he added. “Hopefully other companies would provide schemas, and then we would have the benefit of just being able to grab it and use it internally for various things that are being discussed, like mud pump control, surge and swab prevention or optimizing hydraulics. There are a number of ways to communicate, with the robust broadband connectivity we have offsite and the large computing AI models we have. The ability to harness the power of that connectivity to directly control the rig is advantageous.”

While the RSS downlink schema is commercially mature, H&P’s second schema – for rate of penetration (ROP) optimization and auto-driller set points – is still in prototype. Mr Fox said H&P expects to hand that schema off to D-WIS later this year.

Five different OFS providers are currently using or intend to use the shared ROP optimizer schema: SLB, Baker Hughes, Halliburton, Corva and NOV. As of July 2026, the schema was live in prototype form on two rigs running third-party ROP optimizers – one in Argentina, one in the US – plus two additional rigs running H&P’s own in-house ROP Optimizer.

Mr Fox noted the company has cycled the prototype through roughly six different rigs over time, including locations in South Texas and West Texas, moving the pilot periodically rather than running it continuously on the same equipment.

H&P’s validation window for the ROP schema runs 60 to 90 days per deployment, sometimes longer. In parallel, the company has already installed the necessary rig-edge hardware across its entire active fleet – 165 FlexRigs globally – so that once the schema clears validation, it can be pushed fleetwide with minimal additional hardware rollout delays.

Structurally, the ROP optimizer schema differs from the RSS downlink schema because it governs a different function – auto-driller set points rather than steering commands. However, some data fields overlap, such as mud pump flow rate and top drive RPM, which can factor into either downlink method depending on which parameter an operator chooses to use.

“With the RSS downlink, the execution is what it is. You’re just trying to see if the RSS tool would react to commands the same way it would with a manual remote directional driller,” Mr Fox said. “The ROP Optimizer is very different. It’s a question of whether the average is better with this schema than it is without it. That’s a lot of evaluation and perfection and improvement, both on our side and with the other OFS providers.” DC