Sun L.H.,University of Science and Technology Beijing |
Sun L.H.,Petrochina |
Li J.H.,Xinjiang Oilfield Company |
Sun C.L.,Petrochina |
And 2 more authors.
Applied Mechanics and Materials | Year: 2014
In order to study the mechanism of salt-bearing polymer flooding, using micro-flow technology, experimental study of salt-bearing polymer flooding residual oil process was carried outin two microscopic models of hydrophilic and lipophilic formation. Its microscopic percolation mechanism wasinspected. In hydrophilic model, after injecting salt-bearing polymer residual oil is capturedand migrated, and there is residual oil drawinganddeformation phenomena which is consistent with common polymer; while flooding process due to larger viscoelasticity of salt-bearing polymer, normal stress is generated in the flow, so the cutting action of the residual oil is obvious. In lipophilic model, after injecting salt-bearing polymer, residual oil migration, the film gathering, interface transport, a bridge and drawing phenomenon happened which is consistent with common polymer; polymer difference between salt-bearing polymer andcommon polymeris that from the ordinary and the residual oil film formed by common polymer is flexible and easier to form emulsion. © (2014) Trans Tech Publications, Switzerland.
Li L.,China University of Petroleum - East China |
Jiang J.,China University of Petroleum - East China |
Liu G.,China University of Petroleum - East China |
Jiang R.,China University of Petroleum - East China |
And 5 more authors.
Well Testing | Year: 2015
Recently, there is an important question about re-fracturing of Yushulin oilfield that determining whether the cracks steering and the main factors. By the software of Fracpro PT analyzing the site fracturing data, the net pressure during construction is about 7.8-17.0 MPa. Currently, the maximum and minimum principal stress difference is about 9.6 MPa-20.6 MPa, and an average of 14.4 MPa. By the re-fracturing stress analysis software, we calculate the evolution of the maximum and minimum stress of difference at different positions, when production under the different conditions of pressure, fracture length and fracture width. The maximum and minimum stress of difference of 5mm slot width, smaller 16 mm slot width than 1.0 MPa; The maximum and minimum stress of difference of 120 m slot length, smaller 60 m slot length than 0.5 MPa; The maximum and minimum stress of difference of production pressure of 22 MPa, smaller 17 MPa than 2.0 MPa. Because the initial maximum and minimum principal stress difference is 16 MPa, the part of the oil wells re-fracturing steering have greater difficulty and difficult to form a new fracture. At present, there are some conducive conditions of the reorientation of re-fracturing and generating new cracks. For example, the maximum and minimum stress of difference is smaller; the width and length of initial fracture is bigger; the production pressure is more and the net pressure is higher during the process of re-fracturing. ©, 2015, Well Testing. All right reserved.
Jiang J.,China University of Petroleum - Beijing |
Yang J.,China University of Petroleum - Beijing |
Liu G.,China University of Petroleum - Beijing |
Yao H.,Yushulin Oilfield Development Company Ltd |
And 3 more authors.
Well Testing | Year: 2013
According to failure situation of fracture operation at deviated well Zhao88-30 in Daqing oilfield, parameters in treating site are analyzed. Meanwhile, by adjusting based fluid viscosity in laboratory, twice core flooding experiments with high pump pressures are conducted. It is shows that core 1# is lugged by base fluid with 68.1 mPa · s with low pore pressure, but the base fluid with 21.6 mPa · s goes through the core 2# with high pore pressure. Results show that the based fracturing fluid with 68.4 mPa · s in site can not enter the formation pore of the super-low permeable formation effectively not to increase pore pressure up to the sum of the minimum principal stress and tensile strength of the sandstone, which is the primary reason for the formation not being adding sand. It also indicates that optimization of fracturing fluid needs interpreting mobility of the based fluid in reservoir, to fulfill the main function of fracture-making to base fluid, that also provides the lessons for much low and the other super-low oil reservoirs.