同心分层注入水嘴尺寸确定方法

Determining method of nozzle size used for concentric layered water injection

周理志 韩国锋 王发清 刘曰武 孟祥娟 牛丛丛

ZHOU Lizhi HAN Guofeng WANG Faqing LIU Yuewu MENG Xiangjuan NIU Congcong

中国石油塔里木油田分公司，新疆库尔勒　841000 中国科学院力学研究所，北京　100190

Tarim Oilfield Company, CNPC, Korla 841000, China Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China

塔里木油田分层注水、注气井存在超深、高温、高压的特点，注入流体物性沿井深变化大，为了满足计算精度，必须充分考虑流体物性的变化。常见的注水水嘴计算方法无法达到精度要求，而注气水嘴的计算方法也未见报道。为此提出了满足塔里木油田分注要求的分层配注水嘴尺寸计算方法，由管柱中的流动得到嘴前压力、注入指数曲线得到注入压力，利用嘴前压力和注入压力，通过嘴流方程得到水嘴尺寸。在计算中需要考虑注水和注气在管流和嘴流方面的差别，充分考虑流体物性随温度和压力的变化，沿井深划分小段进行计算。此外，气体嘴流计算中的容积绝热指数需要通过热力学理论计算得到。在塔里木油田的工程实例中，该方法计算出的尺寸与实际尺寸接近，取得了较好的应用效果。

The layered water and gas injection wells in Tarim Oilfield are characterized by super depth, high temperature and high pressure. The physical properties of injected fluids change greatly along the well depth. In order to ensure calculation accuracy, the changes of physical properties of the fluids must be fully considered. The common calculation methods for water injection nozzles are not adequate, and the calculation method for gas injection nozzle are not reported yet. This paper presents a set of methods for calculation of the sizes of layered water injection nozzles determined as per the requirement for separate layer injection in Tarim Oilfield, then the pre-nozzle pressure can be found by flow in the string and the injection pressure is found by the injection index curve. Then the nozzle sizes can be calculated by nozzle flow equation using the pre-nozzle pressure and injection pressure. The difference of pipe flow and nozzle flow of injected gas and water should be considered during calculation. The changes of physical properties of the fluids with temperature and pressure should also be fully considered. And the calculation should be carried out along the well depth in small sections. The isentropic volume change exponent during gas nozzle flow calculation can be found by thermodynamic theoretical calculation. In the engineering cases of Tarim Oilfield, the sizes calculated with this calculation method are close to the actual sizes, so this method acquires very good applied effect.

10.13639/j.odpt.2015.05.024