MWSS Diatomite 21S Weekly UpdateChevron

Reporting Period: 6/1/2015 – 6/7/2015

Above of Reservoir Tilt Events in MWSS Diatomite 21S area from 6/1/2015 to 6/7/2015

Map as per DOGGR’s letter

Tilt event

Activity Summary

Offset Operator (TRC):• Event #06/03A (on TRC) at 395 feet, observed

North East of sump. Energy observed to have moved towards the Chevron sump, and coupled with increased steam activity (clustered wells on steam) in the South East area, resulted in a sustained high 15 day average of 223 bbls of flow.

• A high flow event of 1,200 bbls pulled from the well 20 sump expression on 6/9/15.

• There have been 6 tilt events in the same location since April 1st and corresponding Chevron Well 20 sump increased flow events.

Chevron:• Since early April, the area under the Well 20

Sump has been in an uplifted state. Energy has been observed moving into the area from off-set operator and Chevron activity. Chevron has reduced steam injection in response.

• Chevron had 2 tilt events above reservoir in the reporting period.

• Chevron is not steaming within 800’ of the Well 20 Sump Expression at this time.

Event # 06/03A

Field Surface Deformation 4 day map (June 4th – June 8th)

Property LineWell 20 sump expression

• Background color: relative surface movement over indicated time period. Red is up, dark blue is down. Upward movement indicates subsurface fluid movement into area.

• This is map illustrates earth elevation which indicates expansion of the subsurface

TRC PropertyChevron Property

Well 20 Sump Volumes(1/1/2014 – 6/7/2015)

6/1/15– 6/7/15

Date15 day Avg.

Volume pulled (bbls)

Daily Volume pulled (bbls)

6/1/2015 236 606/2/2015 192 906/3/2015 184 3206/4/2015 195 3506/5/2015 203 2506/6/2015 213 5506/7/2015 223 500

Start/End of EO1016 Phase 3 TRC steam injection test Estimated start of TRC steaming as per EO1068 - TRC steaming per area of investigation map

TRC Steaming during Phase 3 – Emergency Order 1016

TRC Steaming – Emergency Order

1068

* Chevron is not steaming within 800’ of the Well 20 Sump Expression at this time .

Well 20 Sump area(6/2/2015)

Visual Observations: No new seep locations on Chevron property.

* Chevron is not steaming within 800’ of the Well 20 Sump Expression at this time .

Chevron MWSS 21S Property Line and Well 20 Sump “21S Restricted Entry Area” Do not enter red outlined area without approved safety plan

N

Outline of restricted area

22S TRC

21S CVX

Photo 2 March 2015

Red outlined area should not be entered without approval of the Chevron 21S Diatomite OS. Site specific safe work plans must be developed and approved prior to entry.

Well 20 Sump Expression Area

21S Property Line (dashed line) & Unstable Bank Area

Due to the instability of the embankment between CVX and TRC properties, Chevron has extended the Do Not Enter Area (“21S Restricted Area”) to include the area from the embankment to the flow lines that run west of Chevron wells H225 and 204R. The K-rails no longer define the Do Not Enter Area and will be removed.

This area is outlined in red on the aerial photo.

Chevron requests that no one enters the red outlined area without contacting the Chevron Operations Supervisor and developing a written safe work plan prior to entry. The Chevron Supervisor can be contacted at 661-768-8032.

Chevron will work with the DOGGR to safely obtain photos or other data in this area if access to this area is required.