Virtual Measurement Value During Start-up of Major Offshore Projects

摘要

How?can?you?effectively?manage?the?wells?if?you?do?not?continuously?know?what?they?are?producing??This?is?even?more?the?case?when?the?wells?are?being started‐up?for?the?first?time. FieldWare?Production?Universe?(PU)?is?Shell’s?real?time?well?Virtual?Flow?Measurement?(VFM)?tool, which?is?running?on?60%?of?Shell’s?global?production and?has?enabled?significant?added?value?in?the?areas?of?real?time?surveillance?and?optimization.?Production?Universe?has?now?been?applied?in?the?start‐up of?a?number?of?Shell?offshore?projects?in?the?Arabian?Gulf?and?the?Gulf?of?Mexico.?The?purpose?of?this?paper?is?to?describe?PU?added?value?that?has?been achieved?in?the?following?areas?of?these?project?start‐ups?under?transient?and?steady?state?operations: ‐ Provision?of?well?flow?estimates?from?the?very?start?of?commissioning?for?early?indications?of?well/reservoir?performance ‐ Provision?of?well?flow?estimates?from?the?very?start?of?commissioning?for?more?accurate?hydrocarbon?accounting/allocation; ‐ Calculation?of?gas?flaring?volumes?from?the?very?start?of?commissioning, again?for?more?accurate?hydrocarbon?accounting?and?GHG?emissions; ‐ Replacing?wet?gas?flow?meters?on?individual?offshore?wells?with?equivalent?virtual?flow?meters,?hence?saving?significant?CAPEX?and?OPEX; ‐ Replacing?offshore?bulk?flow?measurement?for?total?platform?gas?and?liquid?exports?with?the?sum?of?the?aforementioned?well?virtual?flow estimate,?again?saving?significant?CAPEX; ‐ Control?of?corrosion/hydrate?prevention?chemical?injection?ppm?based?on?well?flow?estimates?resulting?in?enhanced?pipeline?integrity?and chemicals?OPEX?savings Introduction?and?background Shell?has?had?a?number?of?large?upstream,?offshore?projects?recently?in?various?stages?of?start‐up?and/or?commissioning.?These?projects?are?critical?in terms?of?large?capital?investment,?reserves?contribution?and?degree?of?difficulty?(very?deep?water,?subsea?processing,?long?subsea?multiphase?pipelines, feeding?large?onshore?gas?plants?etc.).?Hence?it?is?imperative?to?start‐up?the?processes?as?quickly?and?efficiently?as?possible?and?yet?maintain?the?highest possible?standards?of?technical?integrity,?safety?and?environmental?impact.?Key?aspects?for?efficient/effective?project?start‐up?are?well/reservoir surveillance?and?hydrocarbon?accounting?–?it?is?important?to?know?how?much?the?wells?are?producing?and?the?composition?of?the?fluid?streams,?for maximum?production,?flow?assurance,?asset?technical?integrity?and?accounting?purposes.?Ideally?this?would?be?achieved?by?using?Multi‐phase?Flow?Meters on?each?of?the?wells?to?physically?and?continuously?measure?the?oil,?gas?and?water?flows,?or?by?routing?the?wells?to?the?Test?Separator?as?they?are progressively?started‐up.?However,?MFMs?may?not?have?been?installed?for?all?wells,?and?for?wells?that?have?them,?they?are?usually?not?commissioned?at?the time?of?well?start‐up?‐?MFM?commissioning?requires?fluid?samples?from?the?wells?–?for?subsea?wells?sampling?is?usually?done?robotically?and?at?a?later?start‐ up?stage.?However,?Virtual?Flow?Meters?(VFMs)?can?be?operational?from?the?very?start?of?production.?Similarly,?test?separators?may?not?be?commissioned at?the?time?of?initial?well?production?and?if?they?are?operational?they?are?not?suitable?for?tracking?production?from?multiple?wells. Hence,?VFM?is?of?significant?value?for?well/reservoir?surveillance?and?hydrocarbon?accounting?from?the?first?instance?of?start‐up,?up?to?the?time?when MFMs?are?effectively?commissioned?and?thereafter?as?effective?insurance?in?case?of?individual?meter?failure.?VFMs?have?also?been?used?for?the?following: ‐ replacing?wet?gas?flow?meters?by?continuously?estimating?well?flows?,?incurring?significant?CAPEX?and?OPEX?savings; ‐ replacing?offshore?bulk?flow?measurement?for?total?platform?gas?and?liquid?exports?with?the?sum?of?the?aforementioned?well?virtual?flow estimates,?again?saving?significant?CAPEX?and?OPEX; ‐ continuous?calculation?of?gas?flaring?volumes?from?the?very?start?of?commissioning, again?fo