###### Abstract
The Amott and USBM methods are robust industry laboratory methods that measure the average wettability of core plugs. These methods, notwithstanding their accuracy and reliability, are not applicable downhole. In many field applications, wettability is classified as water- or oil-wet, masking the complexity of wettability due to these extreme simplifications [6]. The various degrees of wetting, commonly stated as mixed wettability, were first developed by [PERSON] [7]. This wetting condition occurs when the macropores and micropores are wetted by oil and water, respectively. Through their extensive research, [PERSON] and [PERSON] [8] introduced various forms of mixed wettability at the pore level. They defined this phenomenon as the rock surface area having parts of it being wetted by different fluids. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Wettability Techniques** & **Advantages** & **Disadvantages** & **Measurement Principle** \\ \hline \multirow{4}{*}{Contact Angle [4]} & Accurate & Surface heterogeneity can affect reading & Invokes direct observation and measurement of wetting angles \\  & Simple & Camort provide information regarding organic coatings. & Uses a topographic microscope or SEM fitted with a single \\  & & Impurities on after reading. & \\  & & Not applied downhole & \\  & & Liquid drop can form many stable contact angles. & \\  & Reliable & Not effective to measure neutral wettability & \\  & Most reliable and accurate, especially in the neutral wettability region & insensitive near-neutral wettability & Measures the volume of naturally imbibed and forcefully displaced fluids \\  & & Inability to differentiate between important degrees of strong water-wetness & \\  & & No applied downhole & \\  & & No validity as an absolute measurement & \\  & United States Bureau of Mines [10] & Reliable & No validity as an absolute measurement & \\  & It is sensitive to near-neutral wettability. & Camort determine mixed wettability & \\  & & It is sensitive to near-neutral wettability. & \\  & & It can only be measured on plug-size samples. & \\  & & & \\ Nuclear magnetic resonance [11] & Ability to study fractional wettability & Not applied downhole & \\  & & & \\  & Distinguishes between macro-and micro-pores & Requires complex and expensive machinery & Changes in longitudinal relaxation \\  & Does not intervene in the fluid saturation & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & & \\  & & \\  & & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & & \\  & & \\  & & & \\  & & \\  & & & \\  & & \\  & & \\  & & & \\  & & \\  &However, the measurement and predictability of the various types of wettability are complicated and challenging. Many researchers have constantly been trying new ideas and methods in this field. During the past two decades, many researchers have been inclined to predict reservoir wettability with nuclear magnetic resonance (NMR) data at the forefront. This inclination to NMR is due to its non-invasive nature. It is used to measure fluid and solid surface interaction sensitivity and other rock-fluid properties like porosity, pore size distribution, relative permeability, and fluid saturation [12; 13]. The NMR logging tool can quantify the different wettability conditions and is applicable downhole, but it cannot be run in all wells due to economic conditions. This scarceness of NMR logs is unlike conventional wireline logs, which are almost always run in all wells, especially the reservoir section [14]. These conventional wireline logs give essential information about the characteristics of formations in subsurface layers, including physical, mineralogical, and morphological properties. The information provided can be directly or indirectly related to wettability. However, a systematic methodology has not yet been developed to use these logs to quantitatively measure wettability due to complex and non-linear relationships between the wireline logs and wettability.