Expansion of onshore gas field

As part of a gas field expan­sion in Sau­di Ara­bia, an inter­na­tion­al group approached the spe­cial­ists at pump man­u­fac­tur­er Lewa Nikkiso Italy in Feb­ru­ary 2019 to com­mis­sion the plan­ning and deliv­ery of 16 canned motor pumps. The sys­tems that were ordered will be used in Sau­di Ara­bia in raw oil pro­cess­ing and remov­ing unwant­ed by-prod­ucts from the gas flow. In addi­tion to pow­er­ful pump tech­nol­o­gy, it is cru­cial to remove the medi­um reli­ably and safe­ly, since the sub­stances sep­a­rat­ed with this method often form a tox­ic, high­ly cor­ro­sive mix­ture. The Nikkiso Non-Seal pumps being used func­tion with­out dynam­ic seals and also fea­ture twin safe­ty shells con­sist­ing of an inner sta­tor lin­ing and exter­nal pres­sure-resis­tant sta­tor hous­ing. As a result, leak­age and the asso­ci­at­ed risks for the envi­ron­ment and employ­ees can be effec­tive­ly pre­vent­ed. An inte­grat­ed E‑Monitor also ensures increased process safe­ty at the cus­tomer’s onshore instal­la­tion by mon­i­tor­ing the bear­ing con­di­tions of the her­met­i­cal­ly tight pumps. The project is expect­ed to be com­plet­ed in 2020, includ­ing detailed plan­ning and pro­cure­ment plus con­struc­tion and instal­la­tion work.

In the course of raw mate­r­i­al pro­cess­ing, unwant­ed by-prod­ucts are con­tin­u­ous­ly removed from the oil or gas flow. “The unus­able mix­ture of sub­stances that is derived from the clean gas flow most­ly con­sists of hydro­gen sul­fide, car­bon diox­ide, and amines,” explained Ric­car­do Mar­cot­ti, Senior Prod­uct Man­ag­er at Lewa Nikkiso Italy. “Hydro­gen sul­fide is par­tic­u­lar­ly worth men­tion­ing here, since it is a high­ly tox­ic chem­i­cal com­pound even in very low per­cent­age and, dis­solved in water, it is also high­ly cor­ro­sive to pip­ing and equip­ment by sul­fide stress crack­ing.” This is why it is only pos­si­ble to remove unwant­ed by-prod­ucts with con­ven­tion­al pump tech­nol­o­gy to a lim­it­ed extent – the risk of leak­age and thus the release of  hydro­gen sul­fide in the atmos­phere is too high.

Second protecting shell and elimination of dynamic seals

In light of these chal­lenges, the glob­al oil and gas com­pa­ny con­tact­ed Lewa Nikkiso Italy, a sub­sidiary of the Leon­berg pump man­u­fac­tur­er, in Feb­ru­ary 2019 and com­mis­sioned the pro­duc­tion and deliv­ery of a total of 16 Nikkiso Non-Seal canned motor pumps. The pumps are nec­es­sary to guar­an­tee that the tox­ic by-prod­ucts are trans­port­ed with­out com­pli­ca­tions, while avoid­ing neg­a­tive effects on the envi­ron­ment and per­son­nel at the expan­sion of the onshore gas field. “As you can imag­ine, the user’s require­ments for pump qual­i­ty and project orga­ni­za­tion were very detailed,” said Mar­cot­ti. “Above all, the cus­tomer placed pri­or­i­ty on the aspects of pump reli­a­bil­i­ty and safe­ty. Our Nikkiso canned motor pumps were able to meet their stan­dards optimally.”

In total, the deliv­ery to the major cus­tomer from Sau­di Ara­bia includes six type HN23F-D2 canned motor pumps, two type HN24E-D3 mod­els, four pumps in the HN23F-D3 basic design – as well as addi­tion­al four ware­house spare pumps – each mod­el sized for rat­ed per­for­mance con­di­tions. All of the vari­ants being used fea­ture a motor that is inte­grat­ed right into the respec­tive canned motor pump and is pro­tect­ed against leak­age by a seal-weld­ed, cor­ro­sion-resis­tant lin­ing. And the entire motor exte­ri­or is encap­su­lat­ed in a sec­ond leak-proof pro­tec­tive shell. As a result, we can elim­i­nate the pos­si­bil­i­ty the mix­ture will escape and con­t­a­m­i­nate the sur­round­ing area and the envi­ron­ment. “Omit­ting dynam­ic seals has also allowed us to sig­nif­i­cant­ly boost oper­at­ing safe­ty dur­ing the work process,” added Marcotti.

E‑Monitor determines current bearing condition

Absolute process reli­a­bil­i­ty also includes ensur­ing con­stant motor cool­ing to pre­vent imme­di­ate and long-term dam­age to the pump. There­fore, in the canned motor pumps being used, the medi­um being con­veyed cir­cu­lates in the area between the rotor and sta­tor lin­ing, affect­ing the motor tem­per­a­ture while lubri­cat­ing the slide bush­ings at the same time. The inte­grat­ed ther­mostats attached at the over­heat­ing points of the wind­ing mon­i­tor the tem­per­a­ture and switch the motor off in case of over­heat­ing. This pre­vents sub­se­quent damage.

In addi­tion to mon­i­tor­ing the tem­per­a­ture, it is pos­si­ble to check the bear­ing con­di­tion dur­ing pump oper­a­tion. To do this, the sen­sors inte­grat­ed into the sta­tor trans­mit the rel­e­vant mea­sure­ment data to a mod­ern E‑Monitor – for exam­ple, if the rotor leaves the safe oper­at­ing posi­tion due to bear­ing wear. The sen­sors reg­is­ter this type of sta­tus change and report it to the mon­i­tor­ing unit. “A green LED lights up on the dis­play to indi­cate a good bear­ing con­di­tion to the per­son­nel, for exam­ple,” explained Mar­cot­ti.  “A yel­low light, on the oth­er hand, indi­cates that the pump should be checked dur­ing the next sys­tem down­time. If a red LED lights up, the pump must be shut down imme­di­ate­ly.” The device makes it pos­si­ble for cus­tomers to per­form pre­ven­tive main­te­nance work based on bear­ing wear and check that the pump’s direc­tion of rota­tion is cor­rect. As a result, it is not nec­es­sary to mea­sure phase rota­tion dur­ing commissioning.

Everything from a single source

In this major project in Sau­di Ara­bia, Lewa Nikkiso Italy has been entrust­ed with the full spec­trum of project imple­men­ta­tion. This means the sub­sidiary of the Leon­berg Group has been com­mis­sioned with detailed plan­ning and pro­cure­ment, as well as car­ry­ing out the super­vi­sion assis­tance for con­struc­tion and instal­la­tion work. “Thanks to our exten­sive expe­ri­ence with oth­er EPC projects, we will be able to meet all the exist­ing require­ments with­out a prob­lem,” said Mar­cot­ti. “In addi­tion to the nec­es­sary lev­els of safe­ty and reli­a­bil­i­ty, this applies to the spec­i­fi­ca­tions for com­pact­ness and main­te­nance, in par­tic­u­lar.” The mod­u­lar struc­ture of the pumps to be deliv­ered is help­ful here, since they con­sist of just a few com­po­nents. All that is required is straight­for­ward assem­bly and main­te­nance – with­out any spac­er discs or clear­ance set­tings. And no addi­tion­al motor or pump bear­ing lubri­ca­tion is need­ed, since the medi­um being trans­port­ed coats the slid­ing parts on its own. “This makes the pumps extreme­ly easy to main­tain and min­i­mizes expen­sive down­time at the same time,” Mar­cot­ti explained. Deliv­ery of the 16 canned motor pumps is planned for Feb­ru­ary 2020; he expand­ed onshore gas field is expect­ed to start up in 2022.