China s rock drill efficiency

With successful breakthroughs and applications of technologies including the 12000m drill rig, wellbore structure optimization, managed-pressure drilling, efficient drill bits, drilling speed-up, ultra-high temperature resistant and high-density drilling fluids, leakage prevention, cementing, ultra-high temperature and pressure resistant oil testing and completion, and ultra-deep coiled tubing equipment, the number of onshore deep and ultra-deep wells in China has been increasing in recent years. [pdf]

FAQS about China s rock drill efficiency

What has been achieved in China's oil & gas industry?

Continuous improvements have been achieved in technical performance indicators such as the drilling cycle, ROP and other metrics. Over 200 wells successfully drilled with MD exceeding 8000m have enabled China to normalize 8000m ultra-deep onshore drilling, with drilling capacity reaching 9000m.

Does rotary non-percussive drilling cause rock failure?

According to the analysis on the SE values at different drilling conditions in rotary non-percussive drilling, the rock failure before the bit is more related to rotary shear than the axial force. Table 2. Calculation of SE based on different drilling parameters in the field test.

Can China normalize 8000m ultra-deep onshore drilling?

Over 200 wells successfully drilled with MD exceeding 8000m have enabled China to normalize 8000m ultra-deep onshore drilling, with drilling capacity reaching 9000m. Moreover, the well depth of TK-1 has successfully exceeded 10000m, making China the second country in the world to successfully drill onshore vertical well with the depth over 10000m.

Does high ROP imply high drilling efficiency in practical engineering?

Note that high ROP does not imply high drilling efficiency in practical engineering because high ROP accelerates the wear of the drilling bit, thereby prolonging the drilling time. Furthermore, the drilling operators possess a few constraints in selecting the correct ROP parameters to optimize the drilling efficiency.

Why do drilling operators need a new index based on rock properties?

However, drilling operators always change drilling parameters to achieve higher drilling efficiency. Hence, a new index that is only related to rock properties and can be successfully applied under different drilling conditions should be developed to define rock properties.

How does cutting a well affect drilling efficiency?

Excessive cuttings will make it difficult to carry drilling fluid, resulting in the deposition of cuttings at the bottom of the wellbore, and the repeated crushing of the rock at the bottom of the wellbore will affect the drilling time and thus reduce the drilling efficiency.

New rock bits

NRB provides clients with a complete service, from their choice of drill bits to the analysis of drilling results. The company’s engineers analyse customer requests and provide the ideal selection of drill bits to fulfill clients every specific need, including: 1. Drilling: oil and gas, exploration and appraisal wells; and artesian. . NRB’s special wear-resistant composite materials coating and unique design allows for both tungsten carbide inserts (TCI) and steel. . NRB’s high-tech polycrystalline diamond cutters (PDC) drill bits are designed for water, oil, gas and geothermal well drilling. Highly durable steel reinforced with polycrystalline. [pdf]

Drill bits for oil rigs

Rotary drilling bits are usually classified as drag bits or rolling cutter bits according to their design. All drag bits consist of fixed cutter blades that are integral to the body of the bit and rotate as a unit with the drill string. This type of drilling bits dates back to the introduction of the rotary drilling process in the 19th century.. . Dull bit grading is a standard method to grade the bit, and it will also help personnel to understand bit performance better. However, it is sometimes very difficult to understand the. . The drill-off test for any oilfield drilling bits determines the optimum weight on bit and overall bit performance. A given amount of weight is put on the bit, and the draw works brakeis. . The penetration rate that can be achieved by a bit has an inverse effect on the drilling cost per foot. The main factors that affect the penetration rate are 1. bit type 2. formation properties 3. drilling fluid properties 4. bit weight and rotary speed 5. bit hydraulics [pdf]