油基钻井液井筒清洗技术室内研究

油基钻井液在解决南海涠洲12-1油田易垮塌硬脆性泥岩的剥落掉块以及提高钻速、减少井下复杂情况等方面具有较好的应用效果。但是在固井作业完成后,含有钻屑的油基钻井液会牢牢粘附在套管内壁,射孔作业时这些污物将直接影响油井的储层保护效果。因此,室内研制了油基钻井液井筒清洗装置,并开发出针对性的清洗液,该清洗液不仅能对套管内壁上的油膜产生较强的渗透清洗力,并且能防止洗掉的油污造成二次污染,具有较理想的清洗效果,清洗率达90%以上,有效的保护了储层。

Lab study on cleaning oil based drilling fluid in borehole

Oil based drilling fluid applied to Weizhou 12-1 Oilfield in the South China Sea could solve the collapse of the hard and brittle shale,increase drilling rate and reduce borehole problems.However,oil based drilling fluid containing cuttings will firmly adhere to the casing wall after cementing operations,and will directly affect the oil reservoir protection in perforating operations.Therefore,clean out system as well as cleaning fluid has been developed in indoor experiment,which could not only clean out the oil film on the casing wall,but also prevent the secondary pollution by oil flecked fluid.It's proved the system could effectively protect reservoirs and the cleaning ratio is over 90%.