油气藏评价与开发 ›› 2025, Vol. 15 ›› Issue (2): 250-256.doi: 10.13809/j.cnki.cn32-1825/te.2025.02.009

• 油气开发 • 上一篇    下一篇

基于改进SSA-BPNN的煤层气直井井底流压预测研究

余洋1(), 董银涛2, 李云波1, 包宇1, 张立侠1, 孙浩1   

  1. 1.中国石油勘探开发研究院,北京 100083
    2.中海油研究总院有限责任公司,北京 100028
  • 收稿日期:2024-01-08 发布日期:2025-04-01 出版日期:2025-04-26
  • 作者简介:余洋(1992—),男,博士,工程师,主要从事油气田开发研究工作。地址:北京市海淀区学院路20号,邮政编码:100083。E-mail:yuyang2022@petrochina.com.cn
  • 基金资助:
    中国石油科学研究与技术开发项目“海外大型碳酸盐岩油藏高效上产关键技术研究”(2023ZZ19-04)

Research on prediction of bottom hole flowing pressure for vertical coalbed methane wells based on improved SSA-BPNN

YU Yang1(), DONG Yintao2, LI Yunbo1, BAO Yu1, ZHANG Lixia1, SUN Hao1   

  1. 1. PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
    2. CNOOC Research Institute Co., Ltd., Beijing 100028, China
  • Received:2024-01-08 Online:2025-04-01 Published:2025-04-26

摘要:

煤层气资源广泛应用直井开发,采用控压控水的排采制度,井底流压是排采方案设计与设备选型的重要参数,因此,煤层气直井井底流压预测具有重要的意义。为了便捷、准确地预测煤层气直井井底流压,指导煤层气井的控压排采,引入机器学习领域中的反向传播神经网络(BPNN)模型,同时对麻雀搜索算法(SSA)进行改进,耦合构建基于改进麻雀搜索算法-反向传播神经网络(SSA-BPNN)的煤层气直井井底流压预测模型。选取了生产现场常规测量的5个影响井底流压的参数作为井底流压预测模型的输入参数,相对应的井底流压数值作为井底流压预测模型的输出参数。将600组实测数据划分为训练集、验证集与测试集,完成了煤层气直井井底流压预测模型的建立与校验工作。BPNN模型与改进SSA-BPNN模型的验证集平均绝对百分比误差分别为3.10%与0.53%,可以看出利用改进SSA与BPNN的耦合建模,能够解决BPNN易陷于局部最优的问题,提高了煤层气直井井底流压的预测精度。同时将改进SSA-BPNN模型与遗传算法-支持向量回归机(GA-SVR)模型和物理模型解析方法进行对比,结果显示:3种不同模型的平均绝对百分比误差分别为1.318%、4.971%、18.156%,改进SSA-BPNN模型的误差最低,且在井底流压较低时,改进SSA-BPNN模型的预测精度显著提高,展现出较高的准确性与良好的适用性。改进SSA-BPNN模型仅需5个输入参数,减少了输入与计算参数的复杂度,且无须考虑井筒内流体分布情况,可覆盖排采各阶段,在不同压力区间都有较高准确性。

关键词: 煤层气, 麻雀搜索算法, 神经网络, 井底流压, 预测模型

Abstract:

Coalbed methane resources are extensively developed using vertical wells, with controlled-pressure and controlled-water drainage systems. The flowing bottom hole pressure is a crucial parameter in the design of drainage schemes and equipment selection. Therefore, it is of great significance to predict the flowing bottom hole pressure for vertical coalbed methane wells. To conveniently and accurately forecast the flowing bottom hole pressure of vertical coalbed methane and guide their pressure control and drainage, a Backpropagation Neural Network (BPNN) algorithm from the field of machine learning was introduced. Additionally, the Sparrow Search Algorithm (SSA) was improved. These were coupled to establish a forecasting model for flowing bottom hole pressure based on the improved SSA-BPNN approach. Five routinely measured parameters that influence flowing bottom hole pressure were selected as the input parameters for the prediction model, with corresponding bottom hole pressure values as the output parameters. A total of 600 sets of field-measured data were partitioned into training, validation, and testing datasets to develop and validate the forecasting model for vertical coalbed methane wells. The validation set showed that the mean absolute percentage errors for the BPNN model and the Improved SSA-BPNN model on the validation set were 3.10% and 0.53%, respectively. This demonstrated that coupling the Improved SSA and BPNN effectively overcame the propensity of BPNN to converge to local optima, thereby improving the prediction accuracy of flowing bottom hole pressure in a vertical coalbed methane well. Furthermore, the improved SSA-BPNN model was compared with the Genetic Algorithm-Support Vector Regression (GA-SVR) method and the physical model-based analytical method. The results revealed that the mean absolute percentage errors for these three different models were 1.318%, 4.971%, and 18.156%, respectively. The Improved SSA-BPNN model had the lowest error, and its prediction accuracy significantly improved when the flowing bottom hole pressure was low, demonstrating its higher accuracy and strong applicability. The Improved SSA-BPNN model requires only five input parameters, reducing the complexity of input and calculation parameters. It does not require consideration of the fluid distribution within the wellbore and can cover all stages of drainage, maintaining high accuracy across different pressure ranges.

Key words: coalbed methane, sparrow search algorithm, neural network, bottom hole flowing pressure, prediction model

中图分类号: 

  • TE37