New method for plugging channeling in oil field by nitrogen foam

Abstract

In order to present a new method for plugging channeling in oil field, the injection modes and validity period of foam system which plugged the formation water layer were studied by means of the experimental model which simulated the real conditions of oil wells existing channeling. Above all, the influence factors including reservoir pressure, permeability, oil saturation and gas-to-liquid ratio were studied through dynamic experiment. Then, in light of the technology characteristics of foam injection in oil field, the comparison between gas-liquid and liquid-gas injection modes was studied. The result shows that the gas-liquid injection mode can ensure the foam injectivity and plugging performance. The plugging validity of nitrogen foam injected into the formation water layer was evaluated in different plugging pressure gradients by the dynamic method which is more reasonable than the static evaluation method in laboratory. The research demonstrates that the plugging validity period of foam decreases with plugging pressure gradient increasing. If the plugging pressure gradient is 0.15 MPa/m, the validity period is 160 h. Finally, a empirical equation and a plate about the plugging validity and the plugging pressure gradient were obtained for forecasting the validity period of foam.

Keywords

foam system / plugging performance / channeling / injection mode / plugging validity

References

[1] LinW J, ZhangC Y, ZhangH L W X M. Acoustic field in a cased well with a sectorial crossing channel [J]. Acta Acustica, 2005, 30(1): 9-14

[2] LiuY M, ZhaoL X, HanH S, LiY H. Technical analysis of sealing thin layer channeling using external casing packer [J]. Drilling & Production Technology, 2000, 23(2): 44-49

[3] HeYThe cements slurry inflating external casing packer technology and its applications [R], 2004

[4] HartfieldG D. Treatment locks out water [J]. Harts E&P, 2006, 79(7): 55-57

[5] SerightrSGel treatments for reducing channeling in naturally fractured reservoirs [R], 1998

[6] FanguyC JImproved method of cementing solid expandable tubular [R], 2004

[7] MorrisT CInnovative remedial cementing solution provides annular isolation in Du yong B-4 Patrons Cari-gali [R], 2004

[8] YuR Z, BianY N, ZhouS, WangK J, LüQ, ChenC H. Nonlinear flow numerical simulation of low permeability reservoir [J]. Journal of Central South University of Technology, 2012, 19(7): 1980-1987

[9] PortmanL. Cementing through coiled tubing: common errors and correct procedures [R]. SPE 89599, 2004

[10] ZhaoR-b, YueX-a, KeW-q, HouY L. Study on influence factors for stability of nitrogen foam system [J]. Acta Petrolei Sinica, 2009, 30(1): 84-87

[11] LiuH, YeP, LiuY, WangX. Nitrogen foam injection technique and its application in reservoirs with high water cut [J]. Acta Petrolei Sinica, 2010, 31(1): 91-95

[12] LuG-z, ZhangJ-qiao. Study and application of nitrogen foam profile control in heavy oil thermal production [J]. Drilling & Production Technology, 2006, 29(4): 88-90

[13] WuW-x, JiangH-feng. Investigation on divided flow of multivariate foam and factors influencing on its oil-displacement efficiency [J]. Oilfield Chemistry, 2002, 19(2): 173-177

[14] LiZ-m, LiB-f, XuY-h, LinR-y, ShangC-hui. Study on the flow-diversion characteristics of foam and its application [J]. Journal of Xi’an Shiyou University: Natural Science Edition, 2007, 22(2): 100-102

[15] ZhongS-f, GouX-jun. Foam stability evaluation and experiment study of diverting effect [J]. Journal of Southwest Petroleum Institute, 2003, 25(1): 65-66

[16] LiZ-m, SunM-s, LinR-y, LiY, XuY-hui. Laboratory study on foam plugging and selective divided-flow [J]. Acta Petrolia Sinica, 2007, 28(4): 115-118

[17] WangZ-linEOR technology of enhanced foam flooding [M], 2007, Beijing, China Science Press: 20-23