【摘要】：采用CFD-DEM耦合計算模型,利用DEM軟件建立大粒徑(2 cm)、非球體巖屑顆粒的離散元模型,與FLUENT實現(xiàn)無縫耦合并行計算,顆粒間相互作用采用Hertz-Mindlin彈性接觸模型,對大粒徑的、非常規(guī)巖屑顆粒在水平井段的運(yùn)移規(guī)律進(jìn)行了數(shù)值模擬計算。基于鉆井實測數(shù)據(jù),建立水平井段環(huán)空內(nèi)含不同形狀(片狀,立方體狀及球狀)相同等效球體粒徑顆粒的計算模型,展示了井眼環(huán)空內(nèi)顆粒運(yùn)移、沉積狀態(tài),對環(huán)空鉆井液流速、不同形狀的巖屑顆粒運(yùn)移速度進(jìn)行了計算分析,本文還計算得到片狀大粒徑巖屑含量對鉆井液攜巖效果的影響規(guī)律。結(jié)果顯示:2 cm等效體積球體粒徑的顆粒在井眼環(huán)空內(nèi)的運(yùn)移狀態(tài)較差,出現(xiàn)局部堆積;立方體狀顆粒的運(yùn)移效果最差,片狀顆粒次之;在所選用計算條件下,片狀顆粒含量大于10%時會加劇削弱攜巖效果。計算結(jié)果可對鉆井?dāng)y巖問題的研究提供一定的參考價值。
[Abstract]:The discrete element model of large particle size (2 cm), non-spherical cuttings) is established by using CFD-DEM coupling calculation model and DEM software, and the seamless coupling parallel calculation is realized with FLUENT. Hertz-Mindlin elastic contact model is used for the interaction between particles. The migration law of large grain diameter and unconventional cuttings particles in horizontal well section is simulated and calculated. Based on the measured drilling data, a calculation model with the same equivalent sphere particle size in the annular space of a horizontal well section (flake, cubic and spherical) is established, which shows the migration and deposition state of the particles in the annular space of the wellbore. The velocity of annular drilling fluid and the migration velocity of cuttings with different shapes are calculated and analyzed. The influence of flake and large diameter cuttings content on the rock carrying effect of drilling fluid is also calculated in this paper. The results show that the particle size of 2 cm equivalent volume sphere has poor migration state and local accumulation in the wellbore annulus, and the migration effect of cubic particles is the worst, followed by flake particles. Under the selected calculation conditions, when the content of flake particles is more than 10%, the effect of rock carrying will be aggravated and weakened. The calculated results can provide certain reference value for the study of drilling rock carrying problem.
【作者單位】： 中國石油大學(xué)機(jī)電工程學(xué)院;海洋石油工程(青島)有限公司;中國石油大學(xué)儲運(yùn)與建筑工程學(xué)院;
【基金】：國家自然科學(xué)基金(51374228) 中國博士后科學(xué)基金(2017M612375)資助
【分類號】：TE243
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本文編號：2482564