Key Drilling Technologies in the Block B at the Right Bank of Amu Darya, Turkmenistan

In Block B at the right bank of Amu Darya, Turkmenistan, a great number of boreholes were abandoned due to blowout, lost circulation and pipe sticking during drilling. After analysis was conducted on the existing drilling accidents, further studies were carried out on the effect of"high-pressure secondary gas reservoirs", high-pressure saline aquifers and high-pressure gas reservoirs on the safety of drilling, a follow-up analysis was performed on the phenomenon occurred during new drilling operation. Based on drilling practice of 11 wells, key drilling technologies were developed in terms of casing program, drilling fluid system, well control device and "stable liquid volume" controlled pressure drilling technology. After they were applied in Block B, the success rate of drilling rose from 18.46% to 100%. It was shown that these key drilling technologies not only ensured smooth drilling in Block B at the right bank of Amu Darya, Turkmenistan, but also provided a technical reference for drilling in other blocks.