The Impact of Temperature Pressure on Borehole Fluids Density
-
摘要: 高温高压深井的安全压力窗口窄,井筒内不同深度之间的流体温差和压差大,且井内流体受到地层加热膨胀和液柱压力压缩造成密度变化,因而容易因入井流体初始密度选择不当造成压力失稳。利用自主研制的高温高压流体密度变化测量仪,进行了温度和压力对淡水、隔离液、水泥浆和矿物白油密度的影响试验,得到了相应的关系曲线;筛选出了适合固井水泥浆温度、压力变化的密度模型——Dodson-Standing模型;通过Drillbench软件,分别计算了入井初始密度1.2和2.0 kg/L水基钻井液和油基钻井液,在井下不同地温梯度下的当量静态密度,得到了4幅对应图版,该图版可为高温高压深井的钻井液和固井液密度设计提供参考。试验结果表明,对于井深为5 000 m、井底静态温度为270 ℃的井,入井初始密度1.2 kg/L水基钻井液的密度可降低5.58%,油基钻井液的密度可降低6.41％。Abstract: The safety pressure window is narrow in deep well with HPHT conditions,the differential pressure and differential temperature at different depth of wellbore are very huge;at the same time,the density of the fluid in the well would change when expanding due to formation heat and pressure of fluid column;therefore the improper selection of initial density of in-well fluid would lead to pressure instability.With independently developed HTHP fluid density measuring apparatus,the experiment was conducted to test the influence of temperature and pressure on fresh water,spacer fluid,water mud and mineral oil density and relevant curves were obtained;the proper density model for temperature and pressure change in well cementation was selected—Dodson-Standing Model;With Drillbench software,the water-based and oil-based drilling fluid with initial in-well density of 1.2 kg/L and 2.0 kg/L was calculated,four corresponding curves,including static equivalent density variation curve were acquired under different geo-thermal gradient.These curves could serve as reference to the density design of drilling fluid and cement slurry for deep wells under HTHP conditions.The experiment results indicated that,in the wells deeper than 5000 m with BHST higher than 270 ℃, the density of water-based fluid could be decreased by 5.58% and that of oil-based fluid decreased by 6.41%,compared with the in-well density of 1.2 g/L.
-
Keywords:
- temperature /
- pressure /
- drilling fluid /
- cement slurry /
- density /
- equivalent static density
-
-
[1] 王贵,蒲晓林.高温深井当量静态密度的计算[J].钻井液与完井液,2008,25(1):1-2,5. Wang Gui,Pu Xiaolin.Equivalent static density calculation for high temperature deep wells[J].Drilling Fluid Completion Fluid,2008,25(1):1-2,5. [2] 苏勤,侯绪田.窄安全密度窗口条件下钻井设计技术探讨[J].石油钻探技术,2011,39(3):62-65. Su Qin,Hou Xutian.Research on drilling design techniques for narrow mud weight window[J].Petroleum Drilling Techniques,2011,39(3):62-65. [3] 赵胜英,鄢捷年,王利国,等.高温高压条件下钻井液当量静态密度预测模型[J].石油钻探技术,2009,37(3):48-52. Zhao Shengying,Yan Jienian,Wang Liguo,et al.Prediction model of equivalent drilling fluid density at high temperature and high pressure[J].Petroleum Drilling Techniques,2009,37(3):48-52. [4] Adamson K,Birch G,Gao E,et al.High-pressure,high-temperature well construction[J].Oilfield Review,1998(6):36-49.
[5] Kutasov I M.Empirical correlation determines downhole mud density[J].Oil Gas Journal,1988,86(52):61-63.
[6] Peters E J,Chevenver M E,Alhamadah A M.Oilmud:a microcomputer program for predicting oil-based mud densities and static pressures[J].SPE Drilling Engineering,1991,6(1):57-59.
[7] Kemp N P,Thomas D C.Density modeling for pure and mixed-salt brines as a function of composition,temperature and pressure.SPE 16079,1987.
[8] Mcmordie Jr W C,Bland R G,Hauser J M.Effect of temperature and pressure on the density of drilling fluids.SPE 11114,1982.
[9] Hoberock L L,Thomas D C,Nickens H V.Bottom hole mud pressure variations due to compressibility and thermal effects:IADC Drilling Technology Conference,Houston,March 9-11,1982.
[10] Babu D R.Effect of P-ρ-T behocviour of muds on static pressures during deep well drilling[J].SPE Drilling Completion,1996,11(2):91-97.
[11] 汪海阁,郝明惠,杨丽平.高温高压钻井液P-ρ-T特性及其对井眼压力系统的影响[J].石油钻采工艺,2000,22(1):17-21. Wang Haige,Hao Minghui,Yang Liping.The P-ρ-T(pressure-density-temperature)behavior of HPHT drilling fluid and its effect on wellbore pressure calculation[J].Oil Drilling Production Technology,2002,22(1):17-21. [12] GB/T 19139—2003 油井水泥试验方法[S]. GB/T 19139—2003 Procedure for testing well cements[S].
计量
- 文章访问数: 3544
- HTML全文浏览量: 84
- PDF下载量: 3342
下载:
