Research On Temporary Plugging Agent In Hainan 3rd Block

The waterflooding extraction development of Hainan 3rd fault block in Liaohe oil field has entered into middle and late period,and lithology in reservior are mainly powder sandstone and siltstone.The well fluid are priority to enter the high permeable zone or big cracks with small resistance,which are affected by serious non-homogeneity of reservior.On one hand it will extend the time to establish the cycle,on the other it will lead to the decline of reservior permeability,making oil flow channel blocked,oil well productivity reduced,and drainage period extended.About 10 days are needed for 3rd fault block to recover the production before washing or workover operations,so it is urgent to study the temporary plugging technology of low pressure wells reservoir protection applied to the block.For that reason,a kind of complex temporary plugging agent were researched in the paper,which are fitted for reservoir characteristics in Hainan 3rd fault block.The new agent can overcome the defects of formation damage and long drainage period during washing well operations,achieving reservoir protection.The research contents are as follows:(1)Researches on the formula of the new temporary plugging agent.Based on stratigraphic characteristics of Hainan 3rd fault block,the components and contents of vegetable gelation,petroleum resin and some additives like strong strengthening agent and adhesive strengthing agent in the new complex temporary plugging agent are obtained by viscosity experiments,softening degree experiments and oil soluble rate experiments of temporary plugging materials.(2)Performance evaluation for new temporary plugging agent.It included the blocking and blocking removal performances analysis,dissolving capacity evaluation,degradation capacity evaluation with resisting high temperature,anti-salt capacity evaluation,et al.Then the factors affecting the above performances and capacities are researched comprehensively(3)Aiming at typical leakage wells and sensitive wells in Hainan 3rd fault block,temporary plugging well-washing experiments were carried out,and the subsequent temporary plugging effect for washing well were tracked.Then the temporary plugging effect were evaluated and analyzed,which verified the effect of the new temporary plugging agent is remarkable in protecting reservoir.The researches in the paper provide technical supports for solving the problems in washing well and hot-wash paraffin operations,and it also provide reference for reservoir protection technology in simular blocks.