The Successful Use of Both Kinetic Hydrate and Paraffin Inhibitors Together in a Deepwater Pipeline with a High Water Cut in the Gulf of Mexico

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractUnder deepwater operating conditions, hydrates and wax can often form blockages in a pipeline. The resultant costs to remediate the situation include not only those for removing the blockage, but also for lost production.The KHI provided lower operating costs plus better environmental conditions than methanol, which had been used before the well was re-completed.The advantages and disadvantages of this KHI product are reviewed. Some of the advantages of KHIs (compared to methanol) include reduced logistics, removal of the undesirable methanol from the crude, plus no oil/water quality issues.This continuous injection application in the deepwater Gulf of Mexico is special since KHIs have generally not been used there. Most previous continuous injection case histories have been from the North Sea. Also, wax control additives were used in conjunction with the LDHIs.

Pectin as an Extraordinary Natural Kinetic Hydrate Inhibitor

“…Moreover, since pectin exist in many kinds of fruit and vegetables and its content in citrus peel is more than 20.0% 25 as well as its extract processing was mature, pectin is further cheaper than KHIs. Compared with using methanol ($0.33/kg), typically used at 35.0 mass% of produced water, pectin ($12.54/kg) provided a cost saving of approximately $121,792 per month at the intermediate water flow rate of 500BWPD 26 and the cost was reduced by 45.7%. Besides, compared with the commercial KHIs ($23.52/kg), 0.5 mass% pectin can replace 1.0 mass% KHIs, which usage can save almost $397,834 per month 26 in the same water flow rate and make the cost decreased by 73.3%.…”

Review of Kinetic Hydrate Inhibitors Based on Cyclic Amides and Effect of Various Synergists

“…Effect of Concentration, Molecular Weight, Monomer Ratio, and Ring Size on Performance. The impact of the concentration on the IT of many lactam-based polymers was previously presented in Figures 12,19,24,26,and 33. In all of the figures, it was observed that the performance increased with increasing concentration; however, in most cases, the rate of increase in the IT decreased with higher concentration.…”

“…Solvents are removed afterward under reduced pressure by a vacuum rotary evaporator to leave the precipitate. ,,,− The precipitate is washed with anhydrous ethyl ether, , ethyl acetate, , n -hexane, and diethyl ether to remove the residual initiator and residual monomer. The precipitate is finally dried in a vacuum oven − to yield the solid product, which is the polymer.…”

“…Offshore flowlines often operate in these regions and thus are prone to plugging due to hydrate formation. ,,,, The removal of hydrate plugs, if formed, from pipelines is inefficient and time-consuming. ,, Substantial damage to machinery can happen, especially when hydrate plugs are propelled due to significant pressure difference, creating a major safety and environmental hazard . Hence, to safeguard the cost-efficient working of pipelines, hydrate plug accumulation must be effectively prevented. − The most effective solution for hydrate plug inhibition is the use of hydrate inhibitors. − …”

“…At a typical water flow rate of 500 BPD (barrels per day), it can be shown that ∼140 000 dollars per month would be saved if the KHI was considered. Note that there would be additional savings from the low transportation and storage costs of KHIs compared with THIs; however, the downside of using KHIs is that these have a limited inhibition period instead of the indefinite time obtained from THIs. In a BP-operated Eastern Trough Area Project (ETAP), the application of a KHI instead of a THI provided a savings of 40 million U.S. dollars .…”