Metodos pneumaticos intermitentes : analise e comparação

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Practical mIes for the selection between continuous gas-lift (CGL) and intermittent gaslift (IGL), based on the reservoir static pressure and productivity index, are available in the literature; however, almost no guidelines exist for the selection among different IGL designs. The goal of the present work is to elose this gap by comparing the performances of four IGL designs, namely, conventional IGL, IGL with plunger, IGL with chamber, and the novel pig-lift, under diverse reservoir conditions; producing a map of suggested designs for each condition. This paper presents the oil production and gas consumption obtained trom computer simulations ofthe above IGL designs for a typical welI, 1500 m deep, with a 5 ½ in casing and a 2 3/8 in tubing, subjected to various static pressures and productivity indexes; the influence of the values of operational parameters, such as valve port and slug size, are also studied for each design. The mechanicist models employed in the simulations were developed upon Liao; they consist of the sets of time-dependent differential equations that govem the various phases of the process cycle. Special care was taken to generate fulIy elosed cycless to guarantee that fallback effects were properly taken in account. The results show, in some cases, an unexpected better performance of the conventional IGL over the other designs. It is observed that the impact of the fall-back in the welI production is not as adverse as elaimedby previous studies, because part of the liquid film left behind by the gas bubble in one cycle may be caught by the liquid slug in the next cycle and driven out. This process cannot be identified in experiments or computations that reproduce only one IGL cycle

ASSUNTO(S)

petroleo - extração escoamento industria petrolifera engenharia de petroleo

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