List of top Petroleum Production Operations Questions on Offshore Structure asked in GATE PE

An underwater riser with an outer diameter of 250 mm and wall thickness of 20 mm is subjected to tension and pressure. The effective tension is $1200$ kN wherein the internal and external pressures of the riser are $25$ MPa and $6$ MPa, respectively. The true wall tension in the riser is $\times 10^{6}$ N (rounded to two decimal places).
A four–column semi–submersible floater is located offshore. The diameter of each column is $5~\text{m}$. Consider the total displaced weight of seawater of the semi–submersible as $4000~\text{tonnes}$. Assume added mass contribution as $50\%$ of the semi–submersible weight, and seawater density as $1025~\text{kg/m}^3$. (Acceleration due to gravity $=9.81~\text{m/s}^2$.) The natural period of oscillation of the floater in vertical mode is __________ seconds (rounded to one decimal place).
An empty steel pipeline with massless endcaps has an outer diameter, $D$, and thickness, $t$. The density of steel is $7850\ \mathrm{kg/m^3}$. The critical $D/t$ ratio at which the pipeline starts floating in seawater of density $1025\ \mathrm{kg/m^3}$ is _________ (rounded to two decimal places).

Figure shows an inextensible catenary mooring cable in still water. The submerged weight (per meter length), and the anchor radius are 100 kg/m and 50 m, respectively. If horizontal tension ($T_h$) in the catenary is 1600 kg, the catenary length (AB) is ............. m (rounded to two decimal places). 

Select ALL the safety system(s) that is/are required in an offshore platform.
Which of the following offshore rigs has the HIGHEST water depth of operation?

Match the platforms (GROUP I) with appropriate support systems (GROUP II). 
 

The primary function of the thruster in the Dynamic Positioning System of an offshore installation is
Which ONE of the following offshore installations uses Dynamic Positioning System for station keeping?
Which ONE of the following is NOT a primary safety system for offshore installations?
MOPU (in the context of offshore drilling and production systems) stands for
Select the CORRECT firefighting system for electrical switchgear room in an offshore facility.
Solids that may possibly form in the offshore pipelines during the production of oil and gas from deep-water reservoirs are