Offshore oil-and-gas production is characterized by the limited space for field equipment allocation and power units capacity. Accompanying the subsea pipelines construction and maintenance difficulty, this also limits the transportation capacity of products, produced fr om remote wellhead platforms. The article covers the methods which exist in Vietsovpetro JV in terms of reduction of pressure losses during transportation, reduction of wells buffered pressure and improvement of wells production rate. The article provides results on optimization of oil and gas transportation at South and Central Dragon fields areas, wh ere operation of wellhead platform RC-5 and step-wise commissioning of new wells at wellhead platform RC-9 with uncompleted construction of a new gas pipeline RC-5/9 – RP-1 follows the increase of gas and liquid production. To reduce the pressure in oil transportation system RC-DM – RC-4 – RC-5 – RP-1, the technology on transporting the part of associated gas RC-5/9 together with the oil to RP-1 was developed. To that purpose, the adjustable choke at RC-5 was designed and implemented to separate the part of associated gas and direct it to the gas-saturated oil flow. The conducted operation resulted in reducing the pressure within oil and gas transportation system on indicated RCs. During gas injection in amount of 90 thousand m3/day, the pressure in the RC-DM slug catcher reduced from 2,12 till 1,9 MPa, at RC-4 – from 2.03 till 1.8 MPa, at
RC-5 – from 2.2 till 1.75 atm. Additional production volume increased averagely by 327 m3/day for liquids (162 t/day for oil), which gave 11.2 % increment. The economic effect from optimisation within the applied period was more than 1.2. mln USD.
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