Summary
This paper details lessons learned from practical field experiences
concerning the design, construction, and commissioning of a production-chemical
program for a green (new) field development. A competent program requires
the interaction of various specialty-products and -services suppliers,
including experts in flow assurance, modeling, fluid analysis, and specialty
chemicals. All are engaged in the early stages of the project and
retained as resources throughout.
Areas addressed for the design and implementation of a chemical-injection
system (CIS) include the following:
- Exploration. Collected bottomhole samples are used for fluid
characterization and risk assessment of any flow-assurance issues. From
these initial data, prevention and mitigation strategies, including but not
limited to chemical inhibition, are developed. Chemical products can be
developed and/or screened for effectiveness and applicability from this initial
assessment. This includes performance screening,
chemical/chemical-compatibility testing, chemical/material-compatibility
testing, and product stability (which is particularly important for umbilical
applications).
- Facility design. Specifications for the processing system and
equipment are detailed, materials of construction are screened for chemical and
fluid compatibility, volume and deliverability requirements are determined, and
the CISs are designed.
- Facility construction. Monitoring and oversight throughout the construction
process are performed to maintain the integrity of the initial design.
- Operational strategies. Strategies will be developed that address
initial flowback, startup, steady-state, and shut-in techniques.
- Logistic strategies. Strategies will be developed that address
logistical concerns (e.g., product transfers and handovers).
- (Pre) Startup commissioning and testing of equipment. Cleanliness and
operability of the system are an absolute must. The chemical day tanks
and injection lines are flushed to specification.
Chemical-injection issues can be safely and successfully managed in new
(deepwater) projects by proper fluid characterization and risk assessment; a
field-development strategy that includes design, specialty treating chemicals,
and operating plans; the involvement of specialists and specialty providers;
and training and communication.
Introduction
As a result of location and/or depletion, petroleum resources have become
harder to obtain. This difficulty has created a demand for newer and more
sophisticated techniques for the recovery of oil and gas. As a function
of this demand, chemical injection has become an important part in the proper
performance of newly designed production systems, particularly in the deepwater
area of the Gulf of Mexico.
Production chemicals play an important role in the enhancement of oil and
gas production—they control corrosion, prevent organic and inorganic deposits
(e.g., paraffin/wax, asphaltenes, and mineral scales), enhance flow
characteristics, and aid in phase separation. These chemicals can be
applied through a variety of techniques, including topside chemical-injection
equipment and capillary/downhole injection. Regardless of type, any CIS
must be designed to be effective, reliable, forgiving, and redundant.
Chemical injection used in conjunction with system design can maximize the
production capacity of the system. For new, or green, fields that are in
the design phase, the incorporation of chemical injection is valued because of
the resultant tradeoff of capital expenditures (CAPEX) for operating
expenditures (OPEX). The idea of trading CAPEX for OPEX is illustrated in
Fig. 1. During project design and construction, maximum value can be achieved
in minimizing CAPEX by use of proper chemical-injection techniques and
procedures. Minimizing CAPEX is achieved by properly anticipating
flow-assurance problems through risk assessment during design and by
incorporating appropriate mitigation techniques into the construction of the
facility.
At facility startup, maximum value is achieved through efficient
commissioning and troubleshooting. Proper planning for the remediation of any
difficulties will ensure success. Training and communication will be
essential to the success of any project.
This paper discusses issues related to the incorporation of chemical
injection into the design of a new project. In addition to design issues,
suggested actions will be presented that will ease the commissioning and
startup of the CIS. Throughout, lessons learned from practical experience
will be presented where appropriate. It is the authors’ hope that the
suggestions presented here will prevent the statement “on the next platform…”
and aid in getting chemical injection right on this platform.
© 2006. Society of Petroleum Engineers
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History
- Original manuscript received:
14 July 2005
- Meeting paper published:
9 October 2005
- Revised manuscript received:
3 February 2006
- Manuscript approved:
3 February 2006
- Version of record:
20 November 2006
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