Pipeline Safety Interpretation PI-76-0105

Page 1PI-76-0105 May 26, 1976 Mr. J. L. LeBlanc Manager Eastern Production Division Chevron Oil Company P.O. Box 6056 New Orleans, Louisiana 70174 Dear Mr. LeBlanc: This refers to your letter of March 19, 1976, requesting a waiver from compliance with the 48-inch cover requirements of 49 CFR 195.248(a) regarding the construction of a 12-3/4 inch crude oil pipeline in the Gulf of Mexico. As Mr. Furrow of this office advised Mr. Gibilterra by phone on April 15, 1976, it appears from the information contained in your letter that the proposed burial method No. 2 would comply with Section 195.248(b) and thereby obviated the need for a waiver. Our rationale for this finding is that (a) the difficulties which you describe in attaining the 48 inches of cover required by Section 195.248(a) represent and “impracticable” situation within the meaning of Section 195.248(b)(1) and , (2) the method of installation and cement bags to be used will provide theaadditional protection required by Section 195.248(b)(2). Sincerely, SIGNED Cesar DeLeon Acting Director Office of Pipeline Safety Operations#

Page 2Chevron Oil Company The California Company Division P. O. Box 6056 New Orleans, La. 70174 March 19, 1976 Chief, Technical Division Major Pipeline Crossings MTP-10 12-3/4” Crude Oil Pipeline Materials Transportation Bureau Main Pass Block 41 Field Office of Pipeline Safety Operations Job CK- 43131 400 7th Street, Southwest Washington, D.C. 20590 Attention: Mr. Frank Fulton Gentlemen: In reference to 49 CFR part 195, subpart 195.248, Chevron Oil Company requests permission for a variance from aforementioned regulation. At present Chevron is engaged in laying a replacement crude oil and water pipeline from our Main Pass Block 41 Field in the Gulf of Mexico to the shoreline approximately southwest of the field. This line will replace an existing 14" pipeline that has been abandoned in place due to numerous leaks. The approved right of way of this pipeline intersects three other major pipelines (see attached drawing). Two of the lines are crude oil pipelines owned by Gulf Oil Company and Marathon Oil Company. The third line is a major gas transmission line from the Main Pass Area owned by Southern Natural Gas Company. Chevron intends to cross over each of these lines. The crude oil lines are being operated at relatively low pressures (less than 300 psig). Both Chevron and its pipeline contractor feel that these crude oil lines can be crossed with a minimal risk of pollution and personnel safety. However, after evaluation of the crossing of the Southern Natural Gas (SNG) pipeline, there appears to be only two economically feasible alternatives in the method of crossing. 1. Cross Over and Lower the SNG Pipeline This would be necessary so that Chevron's replacement line can meet the required 48 inch burial of 49 CFR 195.248. In order to accomplish this crossing it will be necessary to lower the operating pressure on the SNG line to a minimum of 300 psig to reduce the risk to personnel if the line was damaged during the crossing or lowering operations. Additionally, this reduced pressure requirement would necessitate six oil producers (Chevron is included in these) to be shut in for whatever time it would take to lower the pipeline (and repair any damages) causing a daily curtailment of 130 million cubic feet of natural gas, 89 million cubic feet of which is casinghead gas (Producers could elect to flare such gas to remain on production or shut in all oil production). With regards to such a loss in production, there would be a significant financial loss to SNG, Chevron, as well as the other producers. Thus, this method would be both the most expensive and potentially dangerous. 2. Cross Over but do not Lower the SNG Line In this alternative, Chevron would make the crossing of the SNG line and leave the SNG pipeline untouched. Chevron would then bury its 12-3/4" line to the maximum depth that would allow minimum vertical separation of both lines. Chevron would provide additional pipeline protection over the pipeline (cement in bags) equivalent to the minimum required cover of 48 inches. This variance from the required burial will serve to both reduce the hazard to personnel and equipment and eliminate the need to curtail production into the SNG pipeline. We anticipate that this crossing will be made on or about April 3, 1976. Your earliest approval of burial method No. 2 in lieu of the required cover in 49 CFR 195.248 will be appreciated. If you have any questions concerning this request or require additional information, please feel free to contact Mr. T. V. Gibilterra (1-504-521-5783) or Mr. J. S. Gabert, Jr. (1-504-521-5739) of this office. Yours very truly, J.L. LeBlanc Manager Eastern Production Division#

Page 3TO: CDL FROM: LMFurrow Subj: Chevron's March 19 waiver request. We have four options-- 1. Interpret the 48" burial requirement of 195.248(a) as inapplicable to offshore pipelines because the rule only applies to inland waters. 2. Interpret the 48" burial requirement as applicable but that Chevron's proposal No. 2 is within the exception of 195.248(b) for impracticable situations. 3. Interpret the 48" burial as applicable and grant the waiver. 4. Interpret the 48" burial as applicable but deny the waiver. Recommendation: Option 1, because the regulation is vague as to its offshore applicability and probably couldn't be enforced by criminal penalty. L. M. Furrow, MTP-30#