Research On Wellbore Collapse In Overseas A Zone And Drilling Fluid Optimization

Overseas A block has A relatively rich oil resources,but the area of the geological condition is very complex,and the formation of the region are mainly soft mudstone formation,and the altered clay hydration are likely to happen,the resulting leakage problem is serious,so it is easy to occur in the drilling risk accident,similar to the sidewall collapse accidents often happen,will affect the smooth progress of drilling.In this paper,based on the electron microscope scanning techniques,X-ray diffraction(XRD),Zeta potential analysis technology such as analysis of geological conditions in section A,and on the basis of summarizing the blocks in the drilling borehole wall instability.After analyzing the geological conditions of block A and summarizing the causes of the collapse of the well wall,this paper puts forward the concrete and operable anti-collapse technology,and makes corresponding optimization treatment for the previous drilling fluid technology.Through the analysis of the shale recovery rate,linear expansion and conductivity of the experiment,the existing 22 kinds of different drilling fluid formula made a detailed analysis,and optimization can effectively prevent the collapse of the drilling fluid drilling.Through the indoor experiment,the result showed that silicone polymeric alcohol drilling fluid can effectively prevent the collapse of the interior of the reservoir,based on this,and further optimize the collapse prevention drilling fluid through the field application test of compared with the original drilling fluid,achieved good effect.Therefore,the research results of this paper have great reference value for block A and similar area engineering drilling.