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La Goleta Gas Storage Questions Answered

Southern California Gas Company Officials Detail Elements of Expansion Project


Thursday, May 23, 2013

The Southern California Gas Company would like to add a few billion more cubic feet to its La Goleta Gas Storage Field, a reservoir in use since 1941 that already holds 21.5 billion cubic feet of natural gas and is located between Atascadero Creek and Goleta Beach near More Mesa and the Santa Barbara Airport. Along the way, the company hopes to extract one to five billion cubic feet of previously untapped natural gas as well.

All this and more is detailed in a feature story here. But for those who are seeking more details, what follows is a Q&A that was conducted last month via email with Denise King, the Gas Company’s spokesperson.

La Goleta is one of a handful of storage facilities located around the southern half of the state. Can you explain why these are critical parts of the energy infrastructure?

Southern California Gas Co. (SoCalGas) delivers on average 2.8 billion cubic feet of natural gas daily to nearly 5.8 million customers (representing 20.9 million consumers) throughout central and Southern California. More than 80 percent of the natural gas consumed by our customers is transported into California from out of state, with about 20 percent of the natural gas supply purchased from in-state suppliers. Our pipeline system has the capacity to receive 3.7 billion cubic feet of natural gas per day, but often the amount is much less.

On a cold winter day, natural gas consumption can peak at 5 billion cubic feet per day or more (our record delivery was 5.3 billion cubic feet in a single day in 1991.) During these periods of high demand for natural gas, our pipeline system alone cannot serve the entire customer load. And, when out of state pipelines can’t deliver enough natural gas to meet heavy demand, which might occur on a cold winter day, we must withdraw natural gas stored underground to supplement pipeline supplies.

Historically, how did this site become a storage area?

The La Goleta underground storage field was originally discovered by the General Petroleum Corporation in 1929 (predecessor to Mobil Oil) while drilling for oil. After five years and drilling six wells with no oil found, the oil companies lost interest in the field, but the operator turned to the sale of natural gas.

The first natural gas deliveries from the La Goleta Field were made in 1931 to the Southern Counties Gas Co. From 1931 until the fall of 1941, 15.3 billion cubic feet of natural gas was produced. In the summer of 1939, a small compressor station was constructed and test gas was injected into the underground reservoir. The tests showed the reservoir sand was permeable enough to permit the successful injection of natural gas.

Southern Counties Gas Co. then purchased the surface and mineral rights and built the permanent compressor station by 1941.

Is strategically located? Or more of a historical accident that it came to be here?

The La Goleta storage field is strategically located. It serves to balance the coastal natural gas demand from West Los Angeles (Woodland Hills/ Simi Valley) to San Luis Obispo and is a receptor for coastal natural gas production (both onshore and offshore). It also serves to help meet the instantaneous demand of high power plant load. All of the storage fields are depleted oil and gas fields. La Goleta field was a producing gas field and due to the integrity of the field to hold natural gas and the support it provides on the northern end of the transmission pipeline system, it was tested and placed in service.

Why is now the time to extract virgin gas and expand storage at the facility? How long has this plan been in the works?

This plan was conceptualized and presented to the California Public Utilities Commission (CPUC) for review and approval as a part of the Native Gas Decision. The CPUC approved the plan in 2006. The opportunity to extract native gas and increase the storage capacity was put in place to provide native gas to local residents as well as support growth and demand for natural gas supplies.

How does the benefit the average ratepayer?

The CPUC Native Gas Decision provided a sharing mechanism that would provide a 50/50 split of revenues once the project costs are covered. Ratepayers — our customers — will receive 50 percent of the revenue from the natural gas produced, which will go to help reduce rates. The added storage created will be sold to third parties on an annual or seasonal basis and the proceeds will go to help moderates rates for our customers.

Is there anything to be concerned about related to public safety with this project? Any foreseeable harm to neighbors/beach-goers/etc., or worst case scenarios?

The safety of our customers, employees, and the communities we serve is our top priority. A complete and independent quantitative risk assessment (QRA) was conducted for this project by the County of Santa Barbara through the environmental review process. The QRA identified and evaluated worst case scenarios and determined that events large enough to impact neighbors or the public are very unlikely to occur. The risk was determined to be less than significant.

In 1994, a few Rancho Goleta residents recall a loud noise like a “jet engine” and a “hazy plume” shooting 200 feet into the air. Some evacuated the park. They never heard an explanation. Any idea what that event may have been?

We do not recall an unusual plant operation. We are required by the CPUC to test our emergency shutdown system periodically. More than likely that is what occurred. Two of our supervisors here were working at the plant in 1994 and don’t remember anything unusual that could fit the event described.

People point to the bubbles that are in Atascadero Creek and wonder if they are at all related to the storage reservoirs. Are they?

No. Lab tests have shown it to be a different composition than the natural gas in our reservoir.

There is still no fracking proposed for this project, correct?

Fracking was never planned as a part of this project, and SoCalGas has committed in writing that fracking will not occur in the future.

What type of gas extraction technique will be used?

Gas will flow through a dehydration facility and into a low pressure pipeline system. No artificial lift will be needed since the wells should flow without assistance.

There are concerns that the site relies on old pipes and infrastructure. Is that a valid concern? Are there any plans to upgrade the site at all?

The CPUC takes numerous steps to ensure public safety in the immediate and longer term. The CPUC regularly performs physical inspections, and audits operating/inspection practices and procedures developed by SoCalGas. An annual CPUC audit is performed each year. In addition, the California State Division of Oil, Gas, and Geothermal Resources (DOGGR) provides direction and oversight with respect to the field gathering lines and well design, as well as drilling and completion processes. SoCalGas is confident the field is operating in a safe and reliable manner.

The project explains that the production is expected to take five years, if the new wells are successful, but that it would be allowed to go on until the gas is properly depleted. That has some residents worried. Could the production go on forever if the gas was there?

No, the reservoir is limited in size, as gas is produced from the reservoir the pressure will be reduced. Once the pressure drops to the approximate low pressure pipeline pressure, the gas will not flow from the well and the wells will be converted to storage operations.

What’s the dehydration plant like? Loud, large, or?

It is relatively quiet. There are no large engines or compressors. Pumps, fans, and the sound of gas passing through pipe, fittings, and vessels may be heard. The new dehydration plant will be much smaller than the current plant. The new plant is sized for 20 million cubic feet per day of natural gas (MMCFD), while the current plant has a capacity of 420 MMCFD.

I read a document from last year related to a new agreement with State Lands that appeared to be about rent of the resource and payments related to natural gas that SoCal Gas extracts due to “drainage.” Can you explain that more, and how drainage is tracked?

There is a portion of the field that is operated under a lease agreement with the California State Lands Commission (CSLC). The lease payments are based on the percentage of land held by the CSLC with respect to the entire reservoir. CSLC receives a royalty based on the natural gas withdrawn from the field as well as gas injected into the field. The gas is measured in and out of the field and revenues are calculated and paid.

Has the airport expressed any concerns over the height of the tower?

No, however they do have procedures in place that must be followed to address this issue. Because of our close proximity, we routinely work with airport personnel whenever we use tall equipment (rigs, cranes, etc.) on the property. Specifically for this project, the required information and documentation has been submitted to the FAA, and the required mitigations are included in the environmental document. It’s also worth noting that the height of the rig is significantly lower that the height of the existing fixed radio tower antennas on the property.

Regarding the reported vibrations of some neighbors, SoCal Gas has added bracing to a few homes in the mobile home park. Is it true those are caused by the compressors?

Yes, SoCalGas has installed foundation support structures to address subtle vibration issues caused by our compressors.

Are those fixes handled on a complaint-driven basis?

We are committed to being good neighbors, and have worked closely to address these issues with those neighbors who have contacted us.

Is anything being done in this project to address those compressors? Which is to say, will the proposed project increase or decrease the compressor-related shaking?

The proposed project will have no impact on the current operation of the compressors and the associated vibration. Compression will not be required to inject gas into the new storage reservoir. The reservoir will operate below the high pressure transmission system and therefore gas will be injected directly from the pipeline.

From my reading, the compressors will not be used as part of the future storage. Is that correct?

That is correct. The proposed new storage zone will operate between the low pressure pipeline system and the high pressure pipeline system at a lower pressure than the existing storage zone. This will allow natural gas to be withdrawn into the low pressure system and placed into storage directly from the existing high pressure pipeline system without compression.

Will the lighting on the drill rigs, which I understand will be operating 24/7, illuminate the mobile home park?

Drill rig lighting will likely be visible from certain areas within the park. However, due to the significant distance and the screening from vegetation/trees on the SoCalGas property, we do not expect any impacts to the park from illumination.

Read 511-page environmental report here.

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