摘要
塔中区块奥陶系碳酸盐岩裂缝型储层气侵严重、溢流频发、循环排气时间长和井控难度大等问题长期以来阻碍了该区块的顺利钻探和高效开发,而气侵是导致诸多钻井事故的根本原因。为了有效防治和减缓气侵,通过塔中区块奥陶系储层的地质特征分析和室内砂床实验、静态承压实验、电镜扫描(SEM)实验、配伍性实验和动态污染评价实验,研制出了一套封缝堵气效果好、承压能力强的成膜封缝堵气钻井液体系,体系配方为井浆+2%~3%CY-1+3%~4%木质纤维素+3%~4%GZD,该体系的正向承压能力高达8 MPa,反向承压能力高达1 MPa,抗温性高达180℃以上,在8 MPa的驱替压力下漏失量小于10 mL。除此之外,该体系具有较好的配伍性、滤失性和流变性,为塔中区块奥陶系碳酸盐岩裂缝性储层的安全钻井提供了技术指导。
The Ordovician carbonate fractured reservoirs in Tazhong area have many serious problems, such as serious gas invasion, frequent lost circulation, long cycle time and difficult control. These problems have been hindering the processes of well drilling and reduced efficient development of the block for a long time, while the gas invasion is the most fundamental cause for the drilling accidents. In order to effectively prevent and ease the gas cut, a system of drilling fluid is developed by the analysis of geological characteristics, sand bed experiments, the static pressure test, SEM test, compatibility test and dynamic pollution evaluation experiment, which has good sealing gas ability and strong bearing ability. The analysis of experiments indicates that its thermal stability is more than 180℃ and the pressure bearing capacity could be up to 8 MPa in forward and that could be up to 1 MPa in the opposite direction. Besides, filtration is less than 10 mL under the driving pressure, 8 MPa. What is more, it has good compatibility, filtration and rheological properties. All these provide technology supports and guarantee for the security drilling of Ordovician carbonate reservoirs in Tazhong area.
引文
[1] 程常修,曾时田.天然气井钻井应重点考虑的几个技术问题[J].天然气工业,2002,22(2):50-53.
[2] 柳贡慧,胡志坤,李军,等.压力控制钻井井底压力控制方法[J].石油钻采工艺,2009,31(2):15-18.
[3] 魏武,许期聪,邓虎,等.气体钻井技术在七北101井的应用与研究[J].天然气工业,2005,25(9):48-50.
[4] Yang J,Chen Y,Zhao X.Well unloading technology in gas drilling and its application[J].Petroleum Drilling Techniques,2012,40(6):13-16.
[5] 吴志均,陈刚,郎淑敏,等.天然气钻井井控技术的发展[J].石油钻采工艺,2010,32(5):56-60.
[6] 孙宝江,宋荣荣,王志远.高含硫化氢天然气气侵时的溢流特性[J].中国石油大学学报:自然科学版,2012,36(1):73-79.
[7] 刘伟,伍贤柱,韩烈祥,等.水平井钻井技术在四川长宁-威远页岩气井的应用[J].钻采工艺,2013,36(1):114-115.
[8] 曾明昌,曾时田,毛建华.气井喷漏同存的处理技术研究[J].天然气工业,2005,25(6):42-44.
[9] 许玉强,管志川,庞华,等.深水钻井最大允许气侵溢流量的计算方法[J].天然气工业,2016,36(7):74-80.
[10] 张兴全,周英操,刘伟,等.碳酸盐岩地层重力置换气侵特征[J].石油学报,2014,35(5):958-962.
[11] 卓鲁斌,葛云华,张富成,等.碳酸盐岩油气藏气侵早期识别技术[J].石油学报,2012,33(增刊2):174-180.
[12] 孟胡,周海峰,王雪,等.气侵早期检测新方法[J].科学技术与工程,2014,14(27):21-26.
[13] 隋秀香,周明高,候洪为,等.早期气侵监测声波发生技术[J].天然气工业,2003,23(2):62-63.
[14] 李大奇,康毅力,刘修善,等.基于漏失机理的碳酸盐岩地层漏失压力模型[J].石油学报,2011,32(5):900-904.
[15] 孙超,李根生,康延军,等.控压钻井技术在塔中区块的应用及效果分析[J].石油机械,2010,38(5):27-29.
[16] 赵雄虎,崔胜元.砂床法评价钻井液滤失性可行性研究[J].西部探矿工程,2009,21(5):83-85.