涠洲油田群强水敏储层钻井完井液伤害分析及解堵技术应用

Analysis on Drilling and Completion Fluid Damage and Application of Plugging Technology in Strongly Water Sensitive Reservoir of Weizhou Oilfields

针对涠洲油田群强水敏储层投产后达不到配产要求、采液指数很低、表皮系数较大等问题,选取典型井WZ11-1N-A12Sa作研究对象,找出了储层损害原因,研制了水基乳液复合解堵液HJD-S并对其进行评价,得出该解堵液对油基泥浆滤饼有较好的分散、清洗能力,防破乳能力强,与地层流体、岩石的配伍性好,解堵液对钻完井液污染后的岩心具有较好的解除效果,渗透率恢复值大于100%。现场应用表明,解堵液能有效解除该井涠洲组的堵塞,实现日增油208m3,2012年增油量达4.52×104m3。

In view of that the production requirement was not satisfied with very low fluid productivity index and large skin coefficient after the strong water sensitive reservoir in Weizhou Oilfields was brought into production,an investigation was carried out with Well WZ11-1N-A12 Sa,a typical well,as the object of study. The cause for reservoir damage was identified,and a compound deplugging fluid of water-based emulsion HJD-S was developed. It has been found by evaluating the performance of this compound deplugging fluid of water-based emulsion that it is good in dispersing and cleaning oil-based mud cake with strong anti-demulsification capacity and is well compatible with formation fluid and rocks and that it has good removal effect for the rock core contaminated by drilling and completion fluid with the permeability recovery value higher than 100%. The field application has shown that this deplugging fluid can eliminate the blocking in this well effectively with daily oil production increase of 208 m3. The oil production increase was 4. 52 × 10^4m^3 in 2012.