速度管排水采气实验及模型研究
发布时间：2019-07-01 18:37
【摘要】：针对低压、低渗、低产及有水气藏在开采中后期普遍存在的积液问题,亟需开展排水采气工艺措施以维持气井稳定生产。速度管排水采气工艺能降低井筒的临界携液气流速,减少气液间的滑脱损失,提高气井带液能力。该工艺具有施工简单、一次性投入低、不压井作业、对地层伤害小等优势,其应用越来越广泛。但大牛地气田生产实际表明,部分气井在安装速度管生产后不久,就出现产气量、产液量及油压下降的情况。究其原因是对速度管气井气液两相管流规律和携液机理认识不清,导致对速度管井筒压降预测模型和连续携液临界气流量模型的选择不准确,从而对速度管尺寸的选择不合理,最终导致气井的生产能力下降。为此,本文开展了速度管气液两相流压降实验和连续携液实验,基于实验数据,建立了符合速度管流动规律的压降模型和连续携液气流量计算公式。主要工作如下： (1)根据大牛地气田速度管排水采气井常用的生产管柱尺寸(Φ38.1、Φ50.8mm以及环空φ38mm+φ76mm),选定了相对应的三种管径尺寸(φ40mm、φ、50mm以及环空φ40mm+φ80mm),设计制作了速度管排水采气物理模拟实验装置。实验管路总长8m,可调角度00-90°,可用于模拟速度管排水采气井不同井段气液两相流动。 (2)开展了管径为40、50mm以及小环空内的气液两相流动实验,利用数码相机拍摄了不同流动条件下的流型,并分析了流型变化与压降之间的内在关系。测试了液流速为1-10m3/d、气流速为2-34m/s、倾斜角为15°-77°条件下速度管及小环空内的压降,并分析了这三种因素对压降的影响规律。实验测试的压降为速度管压降模型的推导提供了数据支撑。 (3)基于实验数据,在低液量(1-10m3/d)范围内,对HagedomBrown模型进行修正,建立了适用于速度管气液两相流规律的压降模型。利用大牛地气田34口速度管气井的流压测试数据,对包括修正的HagedornBrown模型在内的8个模型进行了评价,评价结果表明,修正模型的误差最小,为大牛地气田速度管气井井筒压降的计算提供了方法。 (4)开展了速度管及小环空中的连续携液实验,分析了液流速、倾斜角对连续携液临界气流速的影响规律；同时,利用数码相机,捕捉连续携液状态下的流型,揭示了连续携液发生时的流型条件。 (5)基于实验数据,考虑管径、倾斜角、液流量的影响,对Belfroid携液模型的相关系数进行修正,建立了综合的携液修正模型,并利用大牛地气田18口速度管气井的测试数据对其进行验证,准确率为88.9%。 本文建立的速度管压降模型和连续携液气流量模型为大牛地气田速度管排水采气工艺的参数优化设计和携液动态预测提供了方法。
[Abstract]:In view of the problems of low pressure, low permeability, low production and liquid accumulation in the middle and late stage of exploitation, it is urgent to carry out drainage gas production technology measures to maintain the stable production of gas wells. The drainage gas production technology of velocity pipe can reduce the critical liquid carrying gas velocity of wellbore, reduce the slippage loss between gas and liquid, and improve the fluid carrying capacity of gas well. This technology has the advantages of simple construction, low one-time input, no killing operation and less damage to formation, so it is more and more widely used. However, the production practice of Daniudi gas field shows that the gas production, liquid production and oil pressure of some gas wells decrease shortly after the installation of speed tube production. The reason is that the law of gas-liquid two-phase pipe flow and the mechanism of carrying liquid in velocity tube gas well are not clearly understood, which leads to the inaccurate selection of velocity pipe wellbore pressure drop prediction model and continuous liquid carrying critical gas flow model, thus unreasonable selection of velocity tube size, and finally leads to the decrease of gas well production capacity. For this reason, the pressure drop experiment and continuous liquid carrying experiment of gas-liquid two-phase flow in velocity tube are carried out in this paper. based on the experimental data, the pressure drop model and the calculation formula of continuous liquid carrying gas flow rate in accordance with the flow law of velocity tube are established. The main work is as follows: (1) according to the production string dimensions (桅 38.1, 桅 50.8mm and annular 蠁 38mm 蠁 76mm) commonly used in velocity pipe drainage gas production wells in Daniudi gas field, three corresponding pipe diameters (蠁 40mm, 蠁, 50mm and annular 蠁 40mm 蠁 80mm) are selected, and the physical simulation experimental devices of velocity pipe drainage gas production are designed and manufactured. The total length of the experimental pipeline is 8 m and the adjustable angle is 00 掳90 掳. It can be used to simulate the gas-liquid two-phase flow in different well sections of velocity pipe drainage gas wells. (2) the experiments of gas-liquid two-phase flow in 40, 50mm and small annulus were carried out. The flow patterns under different flow conditions were photographed by digital camera, and the internal relationship between the change of flow pattern and pressure drop was analyzed. The pressure drop in the velocity tube and small annulus was measured when the liquid flow rate was 1 鈮，
本文编号：2508710
[Abstract]:In view of the problems of low pressure, low permeability, low production and liquid accumulation in the middle and late stage of exploitation, it is urgent to carry out drainage gas production technology measures to maintain the stable production of gas wells. The drainage gas production technology of velocity pipe can reduce the critical liquid carrying gas velocity of wellbore, reduce the slippage loss between gas and liquid, and improve the fluid carrying capacity of gas well. This technology has the advantages of simple construction, low one-time input, no killing operation and less damage to formation, so it is more and more widely used. However, the production practice of Daniudi gas field shows that the gas production, liquid production and oil pressure of some gas wells decrease shortly after the installation of speed tube production. The reason is that the law of gas-liquid two-phase pipe flow and the mechanism of carrying liquid in velocity tube gas well are not clearly understood, which leads to the inaccurate selection of velocity pipe wellbore pressure drop prediction model and continuous liquid carrying critical gas flow model, thus unreasonable selection of velocity tube size, and finally leads to the decrease of gas well production capacity. For this reason, the pressure drop experiment and continuous liquid carrying experiment of gas-liquid two-phase flow in velocity tube are carried out in this paper. based on the experimental data, the pressure drop model and the calculation formula of continuous liquid carrying gas flow rate in accordance with the flow law of velocity tube are established. The main work is as follows: (1) according to the production string dimensions (桅 38.1, 桅 50.8mm and annular 蠁 38mm 蠁 76mm) commonly used in velocity pipe drainage gas production wells in Daniudi gas field, three corresponding pipe diameters (蠁 40mm, 蠁, 50mm and annular 蠁 40mm 蠁 80mm) are selected, and the physical simulation experimental devices of velocity pipe drainage gas production are designed and manufactured. The total length of the experimental pipeline is 8 m and the adjustable angle is 00 掳90 掳. It can be used to simulate the gas-liquid two-phase flow in different well sections of velocity pipe drainage gas wells. (2) the experiments of gas-liquid two-phase flow in 40, 50mm and small annulus were carried out. The flow patterns under different flow conditions were photographed by digital camera, and the internal relationship between the change of flow pattern and pressure drop was analyzed. The pressure drop in the velocity tube and small annulus was measured when the liquid flow rate was 1 鈮，
本文编号：2508710
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