The In-situ Combustion Development Adjustment In Du 66 Block

Du 66 block adopted to the In-situ Combustion after the development of steam stimulation,and has achieved good development results.However,as the exploit goes,this block needs to take some adjustment measures because of the thin interbedded reservoir properties and historical air turbulence aisle.This paper mainly carries out the following work:(1)Evaluated the effects of the ISC development by analyzing the production data;(2)Established the chemical reactions during the ISC and obtain the thermodynamic parameters corresponding to different reaction stages through the experimental data;(3)Carried out a numerical simulation of one-dimensional tube combustion to verify the rationality of the reaction model and the thermodynamic parameters.(4)Established a simplified geological model of the Du 66 reservoir,and after that accomplished the history matching.(5)Some suggestions about the well pattern,gas injection speed and the perforation position of the injectors and the producers are carried out after the numerical simulation research.The results are as follows:(1)There is a significant difference in the effectiveness of ISC,which is roughly divided into obvious effect,general effect and ineffective;this block is mainly in the high temperature oxidation state;due to the planar heterogeneity and inter-layer contradiction,the reservoirs are displaced unevenly;(2)The activation energies of crude oil in low temperature oxidation,thermal cracking and high temperature oxidation were 68.267k J/mol,71.676k J/mol and 119.398k J/mol,respectively;(3)It is found that the combustion front is a very narrow strip(2～3cm)with a high temperature shown by the numerical simulation of the one-dimensional combustion tube;(4)There are several suggestions for Du 66 block:firstly,it is better to use the 100m×70m linear staggered well pattern during the ISC;secondly,the burning front can maintain a reasonable advance speed when the gas injection rate is between8000m~3/d and 12000m~3/d;thirdly,it is better to perforate the bottom of both the injection well and production well,and then we can take advantage of the gas overburden phenomenon by perforating the bottom part of the production well at the late stage.