The Impact of Non-Rotating Protectors on Composite Casing In Drilling Operations

Composite casing plays a crucial role in the drilling industry, providing a durable and efficient solution for well construction and integrity. Moving beyond the realms of traditional steel casings, composite casings incorporate advanced materials like fiberglass-reinforced polymers and carbon fibers. These innovative materials are not just resilient against corrosion - a persistent challenge in the harsh environments of oil and gas wells - but they also have a lightweight nature. This shift not only streamlines the installation process but also cuts down on overall well construction costs, marking a substantial stride forward in drilling efficiency.

Addressing the Unique Challenges of Composite Casing with WWT Non-Rotating Protectors (NRP)

However, the adoption of composite casing introduces a unique challenge. The standard steel drill string, equipped with steel tool joints (TJ), when in rotation against the comparatively softer composite casing, can lead to considerable wear and reduced wall thickness. Here, WWT International introduces a solution: the Non-Rotating Protectors (NRP).

Strategically installed above the drill pipe (DP) TJ, the NRP plays a crucial role in safeguarding the casing. It creates a necessary standoff, preventing direct contact between the rotating steel TJ and the casing. This innovative design means that, during drilling, it's the NRP's polymer sleeve that slides with the casing, not the rotating steel TJ, thereby significantly extending the casing's lifespan.

To demonstrate the effectiveness of NRPs, WWT International conducted a comprehensive in-house test. The objective? To compare the impact of a protected versus an unprotected TJ on composite casing samples. These samples were mounted in the WWT NRP test fixture shown below in Figure 2, designed to mimic the real-world conditions of a DP TJ rotating against casing downhole. The setup includes a rotating mandrel, which slides against a casing trough under side loading and with mud flow.

Two tests were performed lasting for 4 hours each: Test 1 with a bare (unprotected) TJ, and Test 2 featuring a NRP. The results, summarized in the tables below, clearly demonstrate the protective efficacy of the NRP.

Table 1. Test 1 Parameters and Results, No NRPs:

Table 2. Test 2 Parameters and Results, with NRPs:

Test results show minimal wear to composite casing with WWT NRP (0.3-0.9%) compared to bare TJ (16-20%) even under higher side loading. WWT NRPs provide standoff between the DP TJ and the casing. Instead of a rotating steel TJ, the polymer NRP sleeve would slide against the casing thus minimizing casing wear while drilling.

Furthermore, WWT Non Rotating Protectors were recently used by a major operator in KSA on a partial composite liner, logs confirmed that the composite integrity remained intact. This real-world application further underscores the effectiveness of NRPs in preserving the integrity of composite casings.

Stay Ahead in Drilling Engineering with WWT International

Intrigued by how WWT International's solutions can elevate your drilling operations? Dive deeper into our innovations and their impact on the industry. Visit WWTco.com.

Meet the Author: Rami Bou Hadir

Rami is a Regional Engineer at WWT International, bringing 13 years of experience in product technical support, operations management, and client relations. He is renowned for his hands-on approach and commitment to meeting customer needs. Rami cherishes the family-like atmosphere at WWT, valuing the collaborative spirit and support among team members.