fax 01-972-952-9435. AbstractThe environmental fate and effects of four paraffin and one olefin synthetic based drilling mud (SBM) cuttings discharge offshore Sarawak/Sabah Malaysia were compared approximately 3 and 15 months post discharge. Shallow and deepwater sites were assessed for physical, chemical and biological properties to determine whether paraffin based drilling mud cuttings discharge effects were comparable to olefin based cuttings discharge, and would potentially be acceptable for the discharge of Gas-to-Liquid (GTL) paraffin based cuttings. Prospective ecological risk assessment at each site was used to predict projected depositional area concentrations and toxicity of discharges. Those data were used to select field collection sites. Average retention on cuttings (ROC) for all five sites was 5.3 % (4.2-8.3%). The SBM, measured as Total Extractable Hydrocarbon (TEH) concentrations, were correlated to distance from discharge and were typically near analytical detection beyond near field stations (60 to 400 m) from discharge. Detectable TEH concentrations were predominantly found in 0-4 cm depth of the sediment samples collected from all sites. Both paraffin and olefin cuttings were degraded three months after discharge and continued to show increased degradation 15 months post discharge. Composition of the paraffin SBM changed over time with a loss of n-alkanes and some isoparaffins indicating that paraffin degradation was occurring in the field. Sediment toxicity conducted on several samples from two sites indicated toxicity at sites with high TEH. Pisagan samples containing nalkanes showed toxicity whereas samples that showed no toxicity did not have n-alkanes that have largely degraded. A modeling study determined that with existing bottom oxygen concentration ~2 mg/L, estimated currents at 5-10 cm/s, and aerobic sediments having positive (+) oxidizing reduction potential within 2 cm of surface, aerobic degradation was possible for paraffin (and olefins) and could explain degradation of the paraffin. Both modeling and actual field sampling verified a thin cuttings deposition layer that allowed oxic degradation to occur. Redox correlated with TEH and redox was significantly affected by distance at some sites. Benthic macroinvertebrate surveys limited to two deepwater sites indicated no differences between reference sites having below detection TEH and those sites within the zone of cuttings discharge, although differences were observed between these two sites. Benthic community parameters do not appear to be related to discharged SBM cuttings as measured by TEH concentrations. Degradation of paraffin over time and decreasing concentrations, aerobic surface sediment conditions, and no apparent differences in benthic communities confirm that paraffin SBM cuttings are having minimal environmental impact as presently used in offshore Malaysian coastal environments. UC01

The Changbei tight gas reservoir has presented a number of challenges in successful application of fracture stimulation techniques. In an appraisal program, 4 wells have been fracture stimulated. Issues related to fracture containment and high fluid leak-off in coal layers above and below the sand reservoir have led to a number of design and operation challenges. The fractures placed have led to significant production improvements, up to a factor of 10 over pre-frac production. This paper gives an overview of the treatment operations, and without going into details of fracture design and execution, key aspects are outlined and their implications discussed. Introduction The Changbei gas field is located in the Ordos Basin, which is one of the major gas basin onshore China. The Changbei reservoir comprises of Upper Palaeozoic clastic sandstone (P1S2) in the Shaanxi formation. The development block has a total area of 1588 sq. km and crosses the boundary between the provinces of Shaanxi and Inner Mongolia. At an elevation of around 1100m, the area is mostly semi-desert, with surface terrain dominated by sand dunes. The gas reservoirs are predominantly in the P1S2 sandstone, which is approximately 15 to 35 m thick and at a depth of approximately 2800 m. The reservoirs are channel sands possibly compartmentalised and perhaps more likely, by lithologic variations. The reservoir is hydrostatically pressured, with average permeability varying between 0.1 and 4 mD. The reservoir sandstone is sandwiched between shale and coal layers. As part of the data gathering to firm up field development plan, an appraisal program was carried out. A part of the program was to appraise the potential of hydraulic fracturing stimulation in the P1S2 sandstone. Specifically, 4 vertical wells Y27–11, Y29–10, Chang-1V and Chang-2V, were tested for the effectiveness of propped fracture stimulation. With the exception of Y27–11, these appraisal operations include dedicated pre-frac production tests for information on reservoir quality; fracture stimulation with a single stage treatment; and subsequently, post-frac production tests. Y27–11 only had post-frac production test. The technical objectives of the fracture stimulation campaign were to:demonstrate that placing large hydraulic fracture can significantly increase vertical well post-frac productivity. The fracture provides a large drainage area and also by-passes any drilling induced formation damage;show that it is possible to place such large hydraulic fractures within the geological and reservoir settings of Changbei field; andidentify key challenges and scope for improvement. This paper first gives an overview of the treatment operations. Then, we outline the challenges and learnings in dealing with the subsurface uncertainties, as well as those that arise due to having to operate in a remote area with minimum infrastructure and local contractors. Finally, the propped fracture lengths according to hydraulic fracture models are examined in the light of post-frac production data. Although the well production rate has increased substantially after fracture treatment, the fracture lengths deduced from post-frac production well test are generally shorter than those estimated from hydraulic fracture model. To this end, we postulate some plausible explanations. Fracture Treatments The fracture stimulation appraisal operations spanned from October 1999 to March 2001. Y27–11 was the first well, followed by Y29–10, Chang-1V and Chang-2V. In between the fracture treatment operations, production well tests were carried out. It should be noted that in this region, operation ceases in the winter, as surface temperature drops well below minus 10 degree Celcius.

fax 01-972-952-9435. AbstractThe environmental fate and effects of four paraffin and one olefin synthetic based drilling mud (SBM) cuttings discharge offshore Sarawak/Sabah Malaysia were compared approximately 3 and 15 months post discharge. Shallow and deepwater sites were assessed for physical, chemical and biological properties to determine whether paraffin based drilling mud cuttings discharge effects were comparable to olefin based cuttings discharge, and would potentially be acceptable for the discharge of Gas-to-Liquid (GTL) paraffin based cuttings. Prospective ecological risk assessment at each site was used to predict projected depositional area concentrations and toxicity of discharges. Those data were used to select field collection sites. Average retention on cuttings (ROC) for all five sites was 5.3 % (4.2-8.3%). The SBM, measured as Total Extractable Hydrocarbon (TEH) concentrations, were correlated to distance from discharge and were typically near analytical detection beyond near field stations (60 to 400 m) from discharge. Detectable TEH concentrations were predominantly found in 0-4 cm depth of the sediment samples collected from all sites. Both paraffin and olefin cuttings were degraded three months after discharge and continued to show increased degradation 15 months post discharge. Composition of the paraffin SBM changed over time with a loss of n-alkanes and some isoparaffins indicating that paraffin degradation was occurring in the field. Sediment toxicity conducted on several samples from two sites indicated toxicity at sites with high TEH. Pisagan samples containing nalkanes showed toxicity whereas samples that showed no toxicity did not have n-alkanes that have largely degraded. A modeling study determined that with existing bottom oxygen concentration ~2 mg/L, estimated currents at 5-10 cm/s, and aerobic sediments having positive (+) oxidizing reduction potential within 2 cm of surface, aerobic degradation was possible for paraffin (and olefins) and could explain degradation of the paraffin. Both modeling and actual field sampling verified a thin cuttings deposition layer that allowed oxic degradation to occur. Redox correlated with TEH and redox was significantly affected by distance at some sites. Benthic macroinvertebrate surveys limited to two deepwater sites indicated no differences between reference sites having below detection TEH and those sites within the zone of cuttings discharge, although differences were observed between these two sites. Benthic community parameters do not appear to be related to discharged SBM cuttings as measured by TEH concentrations. Degradation of paraffin over time and decreasing concentrations, aerobic surface sediment conditions, and no apparent differences in benthic communities confirm that paraffin SBM cuttings are having minimal environmental impact as presently used in offshore Malaysian coastal environments. UC01

The optimum development of the Deep Carbonate reservoirs in North Kuwait is key to achieve KOC's gas production targets. To optimize (future) production and accessibility of the various Flow Zones within the Target MT formation, KOC has selected a 4.5" mono-bore design to complete the North Kuwait Gas wells. To further improve understanding of production contribution from different flow zones and to enable selective stimulation and effective testing of flow zones, a trial was conducted in a new well to install a 4.5" 15K rated open-hole Multistage Completion (MSC). The well trajectory was designed with all directional work done before the reservoir section. The deviated reservoir section was drilled successfully to the planned TD. A three stage MSC with a long tail string (for future access to deeper reservoirs) was successfully installed. The bottom and middle stages were successfully stimulated and production tested. Stimulation and testing of the upper stage is planned for the future. To build on the success of this first trial another candidate well has been identified and a second 15K MSC system is expected to be installed in the second half of 2017. This paper describes the best practices and the learning in planning and installation of a first successful open-hole MSC in a High Pressure gas well in Kuwait, as well as recommendations for future MSC installations in deep high pressure gas wells with large variations in reservoir caracteristics.

This paper describes Shell EPA (Shell Exploration & Production in Asia Pacific) efforts and strategies to achieve a step change in safety performance by building a sustainable "Proactive Intervention Culture" (PIC) among her workforce, which will intrinsically motivate people to intervene in unsafe acts and situations because they believe in it, rather than because they are being forced or told to. The paper details the planning and development of the PIC training programme, implementation plan and progress to date by Shell EPA to build a sustainable proactive safety culture among staff and contractors. Case for action Despite the introduction of an intervention (STOP Work) policy and Hearts and Minds tools since early days of this decade, there is still a lack of a true intervention culture, which remains one of the root causes for many safety incidents. The Pro-Active Intervention "I Care for Your Safety" Programme was designed to address this gap, focusing on encouraging staff and contractors to intervene in unsafe acts and situation. Adopting a behavioural rather than a knowledge-based approach, the programme's main objective is to build and embed a sustainable pro-active intervention culture. In order to have an effective intervention culture, the issue of attitude needed to be adequately addressed in our safety systems. We needed to develop a process to breach this barrier (the discomfort). A cross-functional team was set up to design the proactive intervention culture programme with the aim to breach the barrier. Brainstorming sessions were conducted with frontline staff to find out "Why the discomfort exists? (see Figure 1). The session highlighted that the main contributory factor boiled down to 'attitude'. In order to address this issue the following aspects were emphasized in the design process:instilling values and beliefs for proactive interventiondeveloping an understanding and removing barriers that hinder proactive intervention actions andthat people eventually feel comfortable and committed towards supporting a proactive intervention culture thus building a 'Brother's Keeper's" culture at the worksites