Page 227 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Application of Gas Wettability CHAPTER 6 211

Table 6.9 Field Test Comparison of “Zero” Damage Filming Temporary Plugging and Other
Technologies (Low-Permeability Reservoirs)

Number of Well Number Protection Daily Fluid Daily Oil Water Daily Oil Monthly
Compared Measure Quantity Quantity Containing Production Declining
Groups (t/d) (t/d) (%) Under Rate (%)
Differential
Pressure
Unit
(t/m.d.MPa)
1 Height424-1 This 4.5 4.4 3 0.2619 213
technology
Height424 Other latest 7.4 4.6 28 0.2428 8
Height424- domestic 1.1 1 9 0.0158 6
flat 1 technologies
2 Chun 48- This 9.1 8.3 10 0.2311 3
inclined 17 technology
Chun 48- Other latest 13 0.5 96 0.0096 9
inclined 11 domestic
Chun 48-13 technologies 3.3 3.3 0 0.0023 6
3 Liang 20- This 9.9 4.6 44 2.1296 10
inclined 31 technology
Liang 20-17 Other latest 12 11 8 1.5151 14
Liang 20- domestic 2.9 0.5 84 0.1428 19
inclined21 technologies

entire well was enhanced. Also, cleanliness affects the cost and drilling time, as
well as the extension length of horizontal wells [24 28].
Mechanical and chemical cleaning are mainly used while drilling horizontal
and large displacement wells in China and overseas. Cuttings that accumulate
at the well bottom are prevented by washing the well, hole reaming, backing
reaming, and short-range tripping during the drilling process. However, the
operational time is longer and the cost is higher [29,30]. In recent years, low
density, low buoyancy, and high viscosity foam drilling fluid are used for
cleaning wells. The buoyancy of foam drilling liquid has little effect on the
well cleaning, which leads to more cuttings piling up [31]. Yu et al. first pro-
posed that wells could be cleaned by floating cuttings with surfactants to
achieve good results [32]. Phan et al. suggested that oil droplets could be used
to replace bubbles to carry the cuttings. However, there are problems within
adequate adhesion of oil droplets and cuttings [33]. Dong Wei et al. adopted
GOB carrying technology for cuttings during the drilling process of a static 52-
H1Z branch well. Mineral oil and surfactants generate some bubbles and oil
droplets adhere on the surface of cuttings to move them upward, to float and
carry cuttings [34].
This section looks at developing a new kind of cutting carrying agent - FGC-1,
based on the gas wettability theory. When it is added to the drilling fluid, the