摘要
简介了4种对环境无害的固态的水基钻井液处理剂的合成及性能:改性天然高分子类包被剂IND30和降滤失剂NAT20,无萤光白沥青NFA25(部分溶于水、部分溶于油的改性油类物质)及粉状聚合醇PGCS1(EO/PO共聚物)。报道了用膨润土和这4种处理剂配制的各种实验钻井液的组成和性能:基本配方钻井液(钻井液1)、强抑制性钻井液(钻井液2,另加入一种小阳离子页岩抑制剂)、抗盐钙污染钻井液(加入35%NaCl和1%CaSO4),抗膨润土污染钻井液(加入4%钙膨润土)。这4种钻井液在原配制状态和在120℃、140℃滚动16小时后,各流变参数均在合理范围,API滤失量≤5 2mL,HTHP滤失量≤20mL。某油藏储层钻屑在钻井液1、2中于140℃滚动16小时后,回收率分别为91 2%和96 7%;该储层岩心被原配制和在140℃滚动16小时后的钻井液1、2污染后,渗透率恢复率为88 2%～91 6%。4种处理剂溶液,钻井液1、2及两口井使用的钻井液均无毒,EC50>3×104mg/L。该体系多功能水基钻井液已在塔里木、克拉玛依等油田10余口井钻井中获得成功应用,最长裸眼长度达5324 45m,井眼扩大率仅5%～10%。详细介绍了在LG区块使用的钻井液分井段组成、维护及性能。表4参3。
The syntheses and properties of 4 environmentally safe solid additives for water base drilling fluids are introduced briefly and these are: modified natural macromolecular coating (inhibiting) agent IND30 and filtrate loss reducer NAT20; non-fluorescent 'white asphalt' NFA25 (modified oily substances soluble partially in water and in oil); and powdered polyol PGCS1 (EO/PO copolymer). The composition and properties of different experimental drilling fluids (EDFs) prepared with bentonite and the 4 additives are presented and these EDFs are: EDF of basic recept (EDF1); strongly inhibitory EDF (EDF2, with a low molecular shale inhibitor added); EDF resistant to contamination by salt and calcium (with 35% NaCl and 1% CaSO_4 added); and EDF resistant to clay contamination (with additional 4% bentonite). For all these EDFs, as prepared and rolled at 120℃ and 140℃ in 16 hrs, the rheologic characteristics are in proper range, the API filtrate loss is <5.2 mL and the HTHP filtrate loss is <20 mL. The recovery of drilling cuttings of a reservoir stratum is of 91.3% and 96.7% after rolling at 140℃ in 16 hrs in EDFs 1 and 2, respectively. The permeability recovery of the reservoir cores polluted by EDFs 1 and 2, as prepared and rolled at 140℃ in 16 hrs, is in range 88.2-91.6%. The solutions of the 4 additives, the EDFs 1 and 2, and the drilling fluids taken from 2 drilling sites are non-toxic with EC_(50) values >3×10~4 mg/L. The drilling fluids of this multifunctional system have been used successfully in drilling more than 10 wells in Tarim, Karamay, and other oil fields with the longest exposed section of borehole 5324.45 m long and with the enlargement of borehole in diameter only 5-10%. The composition, maintenece, and properties of the drilling fluids used in block LG for different borehole sections are described in some detail.
出处
《油田化学》
CAS
CSCD
北大核心
2004年第4期297-300,共4页
Oilfield Chemistry
