## 4 Emergent Configurations in the IIoT
### Overview of Maritime Operations in Oil and Gas Extraction  
Drilling of reservoir rocks is considered as a major objective of maritime operations with a goal of finding trapped hydrocarbons that are buried in the rocks, for several years. The processes of oil and gas explorations begin by building the _oil rig_ in an exact and location with the aid of a satellite so that trapped hydrocarbons can be optimally explored using a vessel. A _drill bit_ is connected to the sea floor (to a depth ranging between 2 to 11 km) through the aid of a _conductor pipe_, where the bit rotates to drills the rocks and sediments formed below the seabed. _Drill pipes_ are then connected to a conductor pipe which runs down to sea floor after which the conductor pipe is installed into the rock. A _casing pipe_ (with approx. diameter of 50 cm) is inserted into the hole through the conductor pipe to ensure installation firmness. A _cement_ is then poured in between the drilled hole and the inserted casing pipe in order to strengthen and firmly position the casing pipe. During drilling operations, a special _mud_ is injected through the drill pipes to cool the drill bit and for mitigating the gushing of oil and gas from the drilled layers by stabilizing the pressure. The mud is a mixture of clay (for thickness) and fine ground rocks (for weight). This mud is also used for cleaning the bottom of the well by carrying rock fragments to the water surface as it travels through the pipes. When hydrocarbons are found, the oil and gas flow to the surface of the water through the calibrated hole at high pressure and are collected and stored in vessels, where they are subsequently transported onshore for further refining in the petrochemical refineries. During oil drilling operations and transportation, there is a possibility of _oil spillage_ occurring. The spillage constitutes a significant challenge for marine engineers during maritime operations [66]. Oil spillage in the context of maritime oil and gas extraction is described as an accidental release of the drilled petroleum hydrocarbons into the marine ecosystem which consequently pollutes the marine environment. Simple plankton organisms such as bacteria, plants, and animals are adversely affected by oil and gas spillages in the marine environment. Fishes, seabirds, marine mammals (such as dolphins and whales), marine reptiles, sea grasses, and mangroves are organisms that greatly suffer the harmful consequences of oil pollution. These organisms end up losing their habitat/shelter. Toxic chemicals released into seawater from marine oil spillages may cause impairment of cellular functions in these marine organisms which can result into a catastrophic mortality rate of marine lives [67]. Oil spillages are caused by two principal actions that may arise naturally or from anthropogenic activities. The spillage is naturally caused from oil and gas leakages that spring up from the bottom of seawater (or oceans). On the other hand, oil spillages may arise from human (anthropogenic) related activities such as accidental oil spills during oil drilling and refining processes including oil collection, storage and transportation. It can also be caused from intentional anthropogenic activities such as oil  
Figure 5: A refined architecture for realizing ECs [62]. discharges through drains to the marine environment in a sewer system as well as through burning of fuels. Oil on water locator (OWL) is a device that is adopted for sensing and detecting oil spillages in both seawater surfaces and sea depth [68]. Hyperspectral laser-induced fluorescence light detection and ranging (HLIF LIDAR) is the technology that is adopted by the OWL for detecting oil leakages in seawater and oceans [68; 69]. Several remote oil sensing techniques such as radio detection and ranging (Radar), ultraviolet (UV)/infrared (IR) scanners and spectral imaging can be employed for detecting oil spillages.