酯基钻井液研究

A RESEARCH ON ESTER-BASE DRILLING FLUID

近海钻井过程中产生的钻屑通常直接向海洋排放以致形成一个钻屑堆，海底探测发现，使用油基钻井液的钻井过程中所产生的钻屑上残余的矿物油降解速率非常慢，岩屑堆下的动植物被窒息，而且还影响到岩屑堆周围的海洋生命，因为残余的矿物油许多年内都在进行缓慢的有氧生物降解过程，耗尽了油周围水中的氧。因而需要研究既不污染环境又具有优良特性的新型钻井液，文章首先对酯基液的制备和性能以及乳状液配方的优选进行了简单描述，然后对优选出的酯基钻井液配方进行了系统的评价试验。研究结果表明，所研制的酯基钻井液体系具有优良的润滑性和储层保护性，其页岩抑制性介于柴油基和水基钻井液之间，适用于井底温度不超过１２０℃的钻井条件。

The cuttings produced in offshore drilling are almost always discharged into the ocean so as to form a stack of cuttings at the sea floor. Through detecting the sea floor, it is found that the degradation rate of mineral oil left on the cuttings produced in the drilling process by use of oil-base drilling fluid is very slow, which makes the animals and plants under the stack of cuttings he stifled to death and the marine organisms around it be menaced, because a slow biodegradation reacting on the remained mineral oil within many years causes the oxygen in the seawater around the oil to be consumed. Therefore it is necessary to develop a novel drilling fluid that not only can't pollute environment but also retains superior property. Firstly, the preparation and performance of ester-base fluid and the optimization of emulsion formulas are simply described, then a systematical evaluation of the ester-base drilling fluid formula optimized is conducted in the paper. The research result shows that the ester-base drilling fluid system developed is of an excellent lubricity and reservoir damage resistance and its shale inhibition is between the shale inhibition of diesel oil-base drilling fluid and the one of water-base drilling fluid. It is suitable for the drilling condition at the bottomhole temperature of less than 120°C.