Low Pressure System: A Production Enhancement Initiative by PETRONAS
Authors: Abd Aziz Mariam Binti , Ibrahim Zahari B. , Mohamed Nulwhoffal , Latif Nurlizawati 
Published: December 2009

The current topic being discussed rigorously by all oil and gas operators is declining production rates. This has caused them to put more efforts into getting the oil out of their matured reservoirs including PETRONAS.

One of the initiatives by PETRONAS recently was to undergo a short term production enhancement project. There were various recommendations and opportunities evaluated. Among them is the Low Pressure System, which was chosen due to its simplicity and mobility.

The Low Pressure System or LPS in short, is a system that utilises the well test unloading concept, using the common well testing equipment package. It is relatively easy to assemble and is not a permanent structure and can be mobilised from one platform to another. The sizing of the equipment can be customised based on the deck space availability as well as the reservoir potential.

Well candidates for the system are those with low tubing head pressure and flowing with biggest choke size as these wells are unable to flow due to the back pressure effect from the export pipeline.

To date, two fields were tested and the gains were more than initially expected. One of the fields has had all of its idle wells flowing and producing more than 500bopd. This paper will share how the wells were selected, the results and challenges during the implementation of LPS.

Introduction

Across the world, production has gone pass peak oil. Clearly, the days of easy oil have long gone. With soaring demand and depleting reserves, every oil company in the world is scrambling to maximise their production. With matured oil fields, many wells are no longer producing i.e. idle or producing with very little oil. Not so much due to depleted reserves, but due to declining reservoir pressure. In Malaysia, this is no exception as it is estimated that more than 60% of the producing fields have been producing for more than 30 years. Therefore, continuous efforts are needed to ensure the production from these fields is maximised and optimum amount of recoverable oil is being extracted from these matured reservoirs.

One of the many initiatives to optimise field reserves recovery that was introduced by PETRONAS recently was the Short Term Production Enhancement (STPE) Project. The project involved ten matured fields and the study period took two months to complete. It studied all the short term opportunities that can be implemented in the matured fields within the next 6 months.. Various opportunities were evaluated and several recommendations were considered and implemented as a result from the STPE study. One of them is the Low Pressure System, which was chosen for implementation due to two characteristics; simplicity and mobility.

The Low Pressure System or LPS in short, is a system that utilises the well test unloading concept, using common well testing equipment package. The uniqueness of LPS is that it utilises old technology but repackaged as a new solution.

What is LPS?

Low Pressure System or LPS for short is an innovative total solution aimed at enhancing field production within a short time cycle. LPS is a unique integrated subsurface and surface approach encompasses engineering study, system design and system operation as shown in Fig. 1.