Abstract:
The overall performance of any well depends on well inflow performance, downhole-conduit
flow performance and surface-flow performance. The changes made in one component of the
system have an overall effect on the entire system.
The objective of the study is to analyze the performance of 11 gas wells in Titas Gas Field of
Bangladesh Gas Field Company Limited (BGFCL), a subsidiary company of Bangladesh Oil,
Gas and Mineral Corporation (Petrobangla).
The effects of various parameters on overall well performance have been studied. The
parameters considered are:
Separator pressure, flowline size, surface chokc size, tubing size, average reservoir pressure
and different reservoir parameters.
The sensitivity of each parameter has been observed to identify any bottle necking or over
sizing of equipment. In this study, up to date data have been used whereever available,
otherwise values have been reasonably assumed. Then the individual wells have been tied in
the same way as in the field and the effect of a parameter on the whole system has been
observed. Nodal analysis approach has been followed in conducting the system analysis
starting from the outer boundary of the reservoir to the sand face, across the perforations and
completion section to the tubing intake, up the tubing string including any restrictions and
downhole safety valves, the surface choke, the flowline and the separator. For this study, the
software- PIPESIM for Windows was used which uses the principle of nodal analysis method.
In the study, wells TT-l through TT-lO are observed to produce at optimum rate but the
flowline and tubing are generally oversized. Tubing ofTT-ll is found to be restricted; using
optimum size of tubing in the well significantly increases the production rate. Then, in the
integrated models, it is found that change in the choke size of any well does not affect the
performance of other wells. This is quite expected as all the wells are producing in the critical
range of the choke.
