Surveillance In South West Queensland And Cross Border Areas: A Review Of The Surveillance In Gas Fields And The Design Of A Five Year Surveillance Plan
Engineering Honours Degree, 2010
University of Adelaide
Gas reservoirs in the South West Queensland and Cross Border South Australia are abundant but are located within mature fields. Many of these reservoirs have been producing since the early 1980s and have long and well detailed histories. The well testing and surveillance carried out over this period has and is still able to provide an insight into the characteristics of the reservoirs/fields and has helped in field development and production strategies. Surveillance is required throughout the life of a field to monitor reservoir depletion, pressure support, and the remaining potential in the reservoir. This Surveillance is essential to properly manage the field, this can be carried out by many different tools each with their own advantages and disadvantages.
The aim of this study is to provide an understanding of current well testing and surveillance requirements of gas fields in the area, in order to assist in future depletion, development and production strategies. After these requirements are investigated for each field that is studied, a specific 5 year surveillance plan for each field is developed within budget constraints. In order to achieve this it was essentially to create set objectives, these were done after speaking to employees at Santos and determining what were the most common issues.
Surveillance is the process where testing and measurements are undertaken to help the reservoir engineer to track and monitor the performance of a field or reservoir. The types that will be the main focus of the paper are SGS, FGS, MPLT, LET and BHP surveillance tests. The data these tests obtain can be a lot of downhole information to the engineer so that the correct management method for the field can be put in place. Another issue is to quantify the value of the surveillance, as it has no direct value it is important to clearly show the purpose and the goals of the surveillance so that its Value of Information can be worked out for the process.
Six fields were reviewed and their data updated and reviewed, these fields were Baryulah, Challum, Karmona, Munkah, Munkarie and Yanda. Each report contained history, geological setting, production plots for fields and wells, critical factors, recommended work and timelines and in addition to this a new five year plan was also created for the six fields.
After this it was found that surveillance at Santos was lacking in both procedural terms as well as budgetary terms. A new process was devised with the help of Santos employees and external reading. It was found that although hard to quantify there is value in surveillance but to gain this the surveillance process and results needs to be set out clearly. A budget increase was also recommended but only if these procedures were properly followed and the correct use and the training in the use of the surveillance were properly administered.