The synchronous development of drill bit technology and drilling activities
New type of rotary guide device
Recently, there has been an increasing emphasis on the research of drill bits that can be used in rotary steering drilling systems (RSS). These types of drill bits make it possible to design more complex wellbore shapes, including horizontal wells and extended reach wells that were previously unable to be effectively drilled using conventional drilling methods.
This type of system can be divided into two categories, one can be called the "push the bit" type, and the other is the "point the bit" type. Regardless of the type chosen, the selection of drill bits must be matched with the RSS system and formation to ensure the three most basic drilling factors: drilling efficiency, steerability, and stability. By ensuring these parameters, directional control, wellbore quality, and vibration conditions can be optimized.
Focus on hard rock formations
In hard formations, the impact damage, thermal damage, and abrasive wear of PDC teeth can limit their performance. It is generally believed that hard rock formations contain rocks with high compressive strength, but in fact, hard rock formations are only rocks and formations that are difficult to drill into. Due to drilling operations spending up to 80% of the budget on hard rock drilling footage, which only accounts for 20% of the total drilling footage, the correct selection of drill bits is crucial.
In the past, due to the inability of PDC bits to effectively overcome various destructive forces in hard rock formations, cone drills have always dominated the hard rock drilling market. Now, with the continuous development of new technologies, PDC bits have increasingly replaced cone bits in drilling in hard formations.
Casing drilling bit
A casing drill bit helps to reduce the inherent risks during casing and lining operations. Whether during a one-time operation or after drilling the wellbore using conventional methods, challenges such as wellbore instability, wellbore leakage, whether the casing can be lowered to the total depth, and effective drilling into the problematic section can be effectively controlled by drilling down the liner and casing through the problematic section. Placing a full PDC cutting structure on this type of drill bit can solve the previously unattainable needs of drilling or expanding in hard formations, as well as drilling longer wellbore sections.
Hughes Christensen provides this casing bit device. The company's EZCase device includes a special alloy crown, equipped with a full PDC cutting structure at the crown, which can complete drilling and casing in one go, reducing non drilling time and reducing the risk of not being able to lower the casing or liner to the total depth of the wellbore in a problematic wellbore. The use of this new drilling device can also successfully complete wells in formations with severe leakage or instability, including fractured gravel zones, circulation fluid leakage areas, depleted oil and gas reservoirs, and areas with underground blowouts. In addition, the PDC drill bit can drill through the EZCase device, so there is no need for additional milling operations.
Underbalanced drilling bit
Varell International has recently launched a new type of sliding bearing bit, which can meet the needs of specially designed underbalanced drilling bits, such as using air, water mixed fog or foam as the circulating medium.
This air jet sliding bearing drill bit adopts a tungsten carbide tooth cutting structure, specifically designed for effective drilling into formations, thorough cleaning of the wellbore, and drilling in the most economical way, so that the drill bit can achieve high mechanical drilling speed under unbalanced drilling conditions while reducing sliding motion and drill bit wear.
An important feature of this drill bit is the special edge shape of its palm tip around the sealing area of the drill bit, which can prevent shale accumulation and prolong bearing life. In order to protect the seal, a proprietary hard metal is applied to the edge of the palm tip and the leading edge area of the drill bit tooth on the drill bit. Meanwhile, embedding hard alloy teeth on the palm tip can also extend the lifespan of the drill bit.
