A new profile control design based on quantitative identification of steam breakthrough channel in heavy oil reservoirs

Chuan Lu,Wei Xiu,Zhanxi Pang,Huiqing Liu,Xiaohu Dong

doi:10.1007/s13202-013-0079-5

Chuan Lu, Wei Xiu + Show 3 more

Open Access

https://doi.org/10.1007/s13202-013-0079-5

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Abstract

Steam breakthrough has a great negative influence on the development of steam flooding in heavy oil reservoirs. In this article, a new profile control design based on quantitative identification of steam breakthrough channel is introduced. Firstly, dual-sandpack experiments are conducted to study the characteristics and influencing factors of steam breakthrough. Then based on the experimental results as well as pretreatment and combination of geological parameters and production data, comprehensive identification parameter (CIP) is achieved through the analytic hierarchy process to quantitatively describe the degree of steam breakthrough. Afterward, the breakthrough types of production wells are determined by CIP and the volume of breakthrough channels and profile control parameters among the injector and the producers are calculated according to the tapering distribution of steam breakthrough in the process of steam flooding in heavy oil reservoirs. The experiment results show that there exists a large difference between breakthrough channels and non-breakthrough areas in temperature and oil recovery. Permeability contrast is an important factor, which influences the direction of steam breakthrough, and temperature has a great correlation with oil recovery under the heterogeneous condition. The determination of CIP is an attempt to quantify the degree of breakthrough and it combines many factors, which show the difference between the injector and the producer, as well as the difference between producers. All producers of the steam flooding well group can be divided into complete breakthrough wells with CIP over 0.5 and incomplete breakthrough wells with CIP below 0.5 for calculating conveniently. Based on the tapering distribution of the steam breakthrough channel, blocking parameters considering oil drainage radius around the injector, temperature distribution between the injector and the producer and the demand of blocking effect and field reality are obtained to calculate the blocking volume for complete breakthrough wells and incomplete breakthrough wells. This method could be used as a tool to judge breakthrough degree and design profile control parameters for oilfields with heavy oil reservoirs.

Highlights

Steam flooding is one of the most important thermal recovery methods to develop heavy oil reservoirs
A new profile control design based on quantitative identification of steam breakthrough channel is introduced
The breakthrough types of production wells are determined by comprehensive identification parameter (CIP) and the volume of breakthrough channels and profile control parameters among the injector and the producers are calculated according to the tapering distribution of steam breakthrough in the process of steam flooding in heavy oil reservoirs

Summary

Introduction

Steam flooding is one of the most important thermal recovery methods to develop heavy oil reservoirs. If steam breakthrough further intensifies, the steam or hot water front will arrive at the producer At this time, the temperature of the liquid production will rapidly increase. Yu et al (2009) introduced an integrated discrimination exponent method, which is based on screening and handling geological static parameters, production performance and analytical test data to quantitatively describe breakthrough channels in the water flooding process. To their steam breakthrough identification theories, Dong and Liu (2012) uses heat invading volume to quantitatively describe breakthrough channel He describes the bottom hole temperature will suddenly increase when the steam arrives at the producer. A new method of optimization of profile control parameters based on the description of mobility variation and temperature distribution in the process of steam breakthrough in heavy oil reservoirs is elaborated. Sand tube number Length (cm) Oil viscosity (mPa.s) Porosity (%) Permeability (10-3 lm2) Oil saturation (%)

Experiment procedures

Obtain the whole blocking volume

Foam injection

Conclusions